Bump 0.12.11 (#20136 )

[ty] Benchmarks for problematic implicit instance attributes cases (#20133 )
## Summary Add regression benchmarks for the problematic cases in https://github.com/astral-sh/ty/issues/758. I'd like to merge this before https://github.com/astral-sh/ruff/pull/20128 to measure the impact (local tests show that this will "solve" both cases).
2025-08-28 09:45:01 -04:00 · 2025-08-28 15:25:25 +02:00 · 2025-08-28 13:02:50 +00:00 · 2025-08-28 08:56:33 -04:00 · 2025-08-28 14:34:49 +02:00 · 2025-08-27 17:53:57 -07:00
2980 changed files with 103910 additions and 69188 deletions
--- a/.github/workflows/build-binaries.yml
+++ b/.github/workflows/build-binaries.yml
@@ -49,7 +49,7 @@ jobs:
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build sdist"
-        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
+        uses: PyO3/maturin-action@86b9d133d34bc1b40018696f782949dac11bd380 # v1.49.4
        with:
          command: sdist
          args: --out dist
@@ -79,7 +79,7 @@ jobs:
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels - x86_64"
-        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
+        uses: PyO3/maturin-action@86b9d133d34bc1b40018696f782949dac11bd380 # v1.49.4
        with:
          target: x86_64
          args: --release --locked --out dist
@@ -121,7 +121,7 @@ jobs:
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels - aarch64"
-        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
+        uses: PyO3/maturin-action@86b9d133d34bc1b40018696f782949dac11bd380 # v1.49.4
        with:
          target: aarch64
          args: --release --locked --out dist
@@ -177,7 +177,7 @@ jobs:
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
+        uses: PyO3/maturin-action@86b9d133d34bc1b40018696f782949dac11bd380 # v1.49.4
        with:
          target: ${{ matrix.platform.target }}
          args: --release --locked --out dist
@@ -230,7 +230,7 @@ jobs:
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
+        uses: PyO3/maturin-action@86b9d133d34bc1b40018696f782949dac11bd380 # v1.49.4
        with:
          target: ${{ matrix.target }}
          manylinux: auto
@@ -292,6 +292,8 @@ jobs:
            maturin_docker_options: -e JEMALLOC_SYS_WITH_LG_PAGE=16
          - target: arm-unknown-linux-musleabihf
            arch: arm
+          - target: riscv64gc-unknown-linux-gnu
+            arch: riscv64

    steps:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
@@ -304,7 +306,7 @@ jobs:
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
+        uses: PyO3/maturin-action@86b9d133d34bc1b40018696f782949dac11bd380 # v1.49.4
        with:
          target: ${{ matrix.platform.target }}
          manylinux: auto
@@ -319,7 +321,7 @@ jobs:
          githubToken: ${{ github.token }}
          install: |
            apt-get update
-            apt-get install -y --no-install-recommends python3 python3-pip
+            apt-get install -y --no-install-recommends python3 python3-pip libatomic1
            pip3 install -U pip
          run: |
            pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links dist/ --force-reinstall
@@ -370,7 +372,7 @@ jobs:
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
+        uses: PyO3/maturin-action@86b9d133d34bc1b40018696f782949dac11bd380 # v1.49.4
        with:
          target: ${{ matrix.target }}
          manylinux: musllinux_1_2
@@ -435,7 +437,7 @@ jobs:
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
+        uses: PyO3/maturin-action@86b9d133d34bc1b40018696f782949dac11bd380 # v1.49.4
        with:
          target: ${{ matrix.platform.target }}
          manylinux: musllinux_1_2
--- a/.github/workflows/build-docker.yml
+++ b/.github/workflows/build-docker.yml
@@ -40,7 +40,7 @@ jobs:

      - uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3.11.1

-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
+      - uses: docker/login-action@184bdaa0721073962dff0199f1fb9940f07167d1 # v3.5.0
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
@@ -131,7 +131,7 @@ jobs:
            type=pep440,pattern={{ version }},value=${{ fromJson(inputs.plan).announcement_tag }}
            type=pep440,pattern={{ major }}.{{ minor }},value=${{ fromJson(inputs.plan).announcement_tag }}

-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
+      - uses: docker/login-action@184bdaa0721073962dff0199f1fb9940f07167d1 # v3.5.0
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
@@ -169,7 +169,7 @@ jobs:
    steps:
      - uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3.11.1

-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
+      - uses: docker/login-action@184bdaa0721073962dff0199f1fb9940f07167d1 # v3.5.0
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
@@ -276,7 +276,7 @@ jobs:
            type=pep440,pattern={{ version }},value=${{ fromJson(inputs.plan).announcement_tag }}
            type=pep440,pattern={{ major }}.{{ minor }},value=${{ fromJson(inputs.plan).announcement_tag }}

-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
+      - uses: docker/login-action@184bdaa0721073962dff0199f1fb9940f07167d1 # v3.5.0
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -38,7 +38,8 @@ jobs:
      fuzz: ${{ steps.check_fuzzer.outputs.changed }}
      # Flag that is set to "true" when code related to ty changes.
      ty: ${{ steps.check_ty.outputs.changed }}
-
+      # Flag that is set to "true" when code related to the py-fuzzer folder changes.
+      py-fuzzer: ${{ steps.check_py_fuzzer.outputs.changed }}
      # Flag that is set to "true" when code related to the playground changes.
      playground: ${{ steps.check_playground.outputs.changed }}
    steps:
@@ -68,7 +69,6 @@ jobs:
            ':crates/ruff_text_size/**' \
            ':crates/ruff_python_ast/**' \
            ':crates/ruff_python_parser/**' \
-            ':python/py-fuzzer/**' \
            ':.github/workflows/ci.yaml' \
          ; then
              echo "changed=false" >> "$GITHUB_OUTPUT"
@@ -138,6 +138,18 @@ jobs:
              echo "changed=true" >> "$GITHUB_OUTPUT"
          fi

+      - name: Check if the py-fuzzer code changed
+        id: check_py_fuzzer
+        env:
+          MERGE_BASE: ${{ steps.merge_base.outputs.sha }}
+        run: |
+          if git diff --quiet "${MERGE_BASE}...HEAD" -- 'python/py_fuzzer/**' \
+          ; then
+              echo "changed=false" >> "$GITHUB_OUTPUT"
+          else
+              echo "changed=true" >> "$GITHUB_OUTPUT"
+          fi
+
      - name: Check if there was any code related change
        id: check_code
        env:
@@ -238,7 +250,7 @@ jobs:
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
-        uses: rui314/setup-mold@702b1908b5edf30d71a8d1666b724e0f0c6fa035 # v1
+        uses: rui314/setup-mold@7344740a9418dcdcb481c7df83d9fbd1d5072d7d # v1
      - name: "Install cargo nextest"
        uses: taiki-e/install-action@6064345e6658255e90e9500fdf9a06ab77e6909c # v2.57.6
        with:
@@ -296,7 +308,7 @@ jobs:
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
-        uses: rui314/setup-mold@702b1908b5edf30d71a8d1666b724e0f0c6fa035 # v1
+        uses: rui314/setup-mold@7344740a9418dcdcb481c7df83d9fbd1d5072d7d # v1
      - name: "Install cargo nextest"
        uses: taiki-e/install-action@6064345e6658255e90e9500fdf9a06ab77e6909c # v2.57.6
        with:
@@ -381,7 +393,7 @@ jobs:
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
-        uses: rui314/setup-mold@702b1908b5edf30d71a8d1666b724e0f0c6fa035 # v1
+        uses: rui314/setup-mold@7344740a9418dcdcb481c7df83d9fbd1d5072d7d # v1
      - name: "Build"
        run: cargo build --release --locked

@@ -406,7 +418,7 @@ jobs:
          MSRV: ${{ steps.msrv.outputs.value }}
        run: rustup default "${MSRV}"
      - name: "Install mold"
-        uses: rui314/setup-mold@702b1908b5edf30d71a8d1666b724e0f0c6fa035 # v1
+        uses: rui314/setup-mold@7344740a9418dcdcb481c7df83d9fbd1d5072d7d # v1
      - name: "Build tests"
        shell: bash
        env:
@@ -429,7 +441,7 @@ jobs:
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install cargo-binstall"
-        uses: cargo-bins/cargo-binstall@dd6a0ac24caa1243d18df0f770b941e990e8facc # v1.14.3
+        uses: cargo-bins/cargo-binstall@0dca8cf8dfb40cb77a29cece06933ce674674523 # v1.15.1
        with:
          tool: cargo-fuzz@0.11.2
      - name: "Install cargo-fuzz"
@@ -443,7 +455,7 @@ jobs:
    needs:
      - cargo-test-linux
      - determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && needs.determine_changes.outputs.parser == 'true' }}
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.parser == 'true' || needs.determine_changes.outputs.py-fuzzer == 'true') }}
    timeout-minutes: 20
    env:
      FORCE_COLOR: 1
@@ -451,7 +463,7 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+      - uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0
      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
        name: Download Ruff binary to test
        id: download-cached-binary
@@ -633,7 +645,7 @@ jobs:
      - cargo-test-linux
      - determine_changes
    # Only runs on pull requests, since that is the only we way we can find the base version for comparison.
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && github.event_name == 'pull_request' && needs.determine_changes.outputs.ty == 'true' }}
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && github.event_name == 'pull_request' && (needs.determine_changes.outputs.ty == 'true' || needs.determine_changes.outputs.py-fuzzer == 'true') }}
    timeout-minutes: 20
    steps:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
@@ -652,7 +664,7 @@ jobs:
          branch: ${{ github.event.pull_request.base.ref }}
          workflow: "ci.yaml"
          check_artifacts: true
-      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+      - uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0
      - name: Fuzz
        env:
          FORCE_COLOR: 1
@@ -682,7 +694,7 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: cargo-bins/cargo-binstall@dd6a0ac24caa1243d18df0f770b941e990e8facc # v1.14.3
+      - uses: cargo-bins/cargo-binstall@0dca8cf8dfb40cb77a29cece06933ce674674523 # v1.15.1
      - run: cargo binstall --no-confirm cargo-shear
      - run: cargo shear

@@ -703,7 +715,7 @@ jobs:
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
+        uses: PyO3/maturin-action@86b9d133d34bc1b40018696f782949dac11bd380 # v1.49.4
        with:
          args: --out dist
      - name: "Test wheel"
@@ -722,13 +734,13 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+      - uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0
      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
        with:
          node-version: 22
      - name: "Cache pre-commit"
-        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
        with:
          path: ~/.cache/pre-commit
          key: pre-commit-${{ hashFiles('.pre-commit-config.yaml') }}
@@ -765,7 +777,7 @@ jobs:
      - name: "Install Rust toolchain"
        run: rustup show
      - name: Install uv
-        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+        uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0
      - name: "Install Insiders dependencies"
        if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
        run: uv pip install -r docs/requirements-insiders.txt --system
@@ -897,7 +909,7 @@ jobs:
          persist-credentials: false

      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
-      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+      - uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0

      - name: "Install Rust toolchain"
        run: rustup show
@@ -930,7 +942,7 @@ jobs:
          persist-credentials: false

      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
-      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+      - uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0

      - name: "Install Rust toolchain"
        run: rustup show
--- a/.github/workflows/daily_fuzz.yaml
+++ b/.github/workflows/daily_fuzz.yaml
@@ -34,11 +34,11 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+      - uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
-        uses: rui314/setup-mold@702b1908b5edf30d71a8d1666b724e0f0c6fa035 # v1
+        uses: rui314/setup-mold@7344740a9418dcdcb481c7df83d9fbd1d5072d7d # v1
      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
      - name: Build ruff
        # A debug build means the script runs slower once it gets started,
--- a/.github/workflows/mypy_primer.yaml
+++ b/.github/workflows/mypy_primer.yaml
@@ -11,6 +11,7 @@ on:
      - "crates/ruff_python_parser"
      - ".github/workflows/mypy_primer.yaml"
      - ".github/workflows/mypy_primer_comment.yaml"
+      - "scripts/mypy_primer.sh"
      - "Cargo.lock"
      - "!**.md"

@@ -38,7 +39,7 @@ jobs:
          persist-credentials: false

      - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+        uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0

      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
        with:
@@ -81,7 +82,7 @@ jobs:
          persist-credentials: false

      - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+        uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0

      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
        with:
--- a/.github/workflows/publish-pypi.yml
+++ b/.github/workflows/publish-pypi.yml
@@ -22,7 +22,7 @@ jobs:
      id-token: write
    steps:
      - name: "Install uv"
-        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+        uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0
      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
        with:
          pattern: wheels-*
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -61,7 +61,7 @@ jobs:
    env:
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
-      - uses: actions/checkout@09d2acae674a48949e3602304ab46fd20ae0c42f
+      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493
        with:
          persist-credentials: false
          submodules: recursive
@@ -124,19 +124,19 @@ jobs:
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      BUILD_MANIFEST_NAME: target/distrib/global-dist-manifest.json
    steps:
-      - uses: actions/checkout@09d2acae674a48949e3602304ab46fd20ae0c42f
+      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493
        with:
          persist-credentials: false
          submodules: recursive
      - name: Install cached dist
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0
        with:
          name: cargo-dist-cache
          path: ~/.cargo/bin/
      - run: chmod +x ~/.cargo/bin/dist
      # Get all the local artifacts for the global tasks to use (for e.g. checksums)
      - name: Fetch local artifacts
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0
        with:
          pattern: artifacts-*
          path: target/distrib/
@@ -175,19 +175,19 @@ jobs:
    outputs:
      val: ${{ steps.host.outputs.manifest }}
    steps:
-      - uses: actions/checkout@09d2acae674a48949e3602304ab46fd20ae0c42f
+      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493
        with:
          persist-credentials: false
          submodules: recursive
      - name: Install cached dist
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0
        with:
          name: cargo-dist-cache
          path: ~/.cargo/bin/
      - run: chmod +x ~/.cargo/bin/dist
      # Fetch artifacts from scratch-storage
      - name: Fetch artifacts
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0
        with:
          pattern: artifacts-*
          path: target/distrib/
@@ -251,13 +251,13 @@ jobs:
    env:
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
-      - uses: actions/checkout@09d2acae674a48949e3602304ab46fd20ae0c42f
+      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493
        with:
          persist-credentials: false
          submodules: recursive
      # Create a GitHub Release while uploading all files to it
      - name: "Download GitHub Artifacts"
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0
        with:
          pattern: artifacts-*
          path: artifacts
--- a/.github/workflows/sync_typeshed.yaml
+++ b/.github/workflows/sync_typeshed.yaml
@@ -65,7 +65,7 @@ jobs:
        run: |
          git config --global user.name typeshedbot
          git config --global user.email '<>'
-      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+      - uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0
      - name: Sync typeshed stubs
        run: |
          rm -rf "ruff/${VENDORED_TYPESHED}"
@@ -117,7 +117,7 @@ jobs:
        with:
          persist-credentials: true
          ref: ${{ env.UPSTREAM_BRANCH}}
-      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+      - uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0
      - name: Setup git
        run: |
          git config --global user.name typeshedbot
@@ -155,7 +155,7 @@ jobs:
        with:
          persist-credentials: true
          ref: ${{ env.UPSTREAM_BRANCH}}
-      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+      - uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0
      - name: Setup git
        run: |
          git config --global user.name typeshedbot
--- a/.github/workflows/ty-ecosystem-analyzer.yaml
+++ b/.github/workflows/ty-ecosystem-analyzer.yaml
@@ -33,7 +33,7 @@ jobs:
          persist-credentials: false

      - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+        uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0

      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
        with:
--- a/.github/workflows/ty-ecosystem-report.yaml
+++ b/.github/workflows/ty-ecosystem-report.yaml
@@ -29,7 +29,7 @@ jobs:
          persist-credentials: false

      - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
+        uses: astral-sh/setup-uv@4959332f0f014c5280e7eac8b70c90cb574c9f9b # v6.6.0

      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
        with:
--- a/.github/workflows/typing_conformance.yaml
+++ b/.github/workflows/typing_conformance.yaml
@@ -54,6 +54,9 @@ jobs:

      - name: Compute diagnostic diff
        shell: bash
+        env:
+          # TODO: Remove this once we fixed the remaining panics in the conformance suite.
+          TY_MAX_PARALLELISM: 1
        run: |
          RUFF_DIR="$GITHUB_WORKSPACE/ruff"

@@ -63,15 +66,15 @@ jobs:

            echo "new commit"
            git rev-list --format=%s --max-count=1 "$GITHUB_SHA"
-            cargo build --release --bin ty
-            mv target/release/ty ty-new
+            cargo build --bin ty
+            mv target/debug/ty ty-new

            MERGE_BASE="$(git merge-base "$GITHUB_SHA" "origin/$GITHUB_BASE_REF")"
            git checkout -b old_commit "$MERGE_BASE"
            echo "old commit (merge base)"
            git rev-list --format=%s --max-count=1 old_commit
-            cargo build --release --bin ty
-            mv target/release/ty ty-old
+            cargo build --bin ty
+            mv target/debug/ty ty-old
          )

          (
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,105 @@
 # Changelog

+## 0.12.11
+
+### Preview features
+
+- \[`airflow`\] Extend `AIR311` and `AIR312` rules ([#20082](https://github.com/astral-sh/ruff/pull/20082))
+- \[`airflow`\] Replace wrong path `airflow.io.storage` with `airflow.io.store` (`AIR311`) ([#20081](https://github.com/astral-sh/ruff/pull/20081))
+- \[`flake8-async`\] Implement `blocking-http-call-httpx-in-async-function` (`ASYNC212`) ([#20091](https://github.com/astral-sh/ruff/pull/20091))
+- \[`flake8-logging-format`\] Add auto-fix for f-string logging calls (`G004`) ([#19303](https://github.com/astral-sh/ruff/pull/19303))
+- \[`flake8-use-pathlib`\] Add autofix for `PTH211` ([#20009](https://github.com/astral-sh/ruff/pull/20009))
+- \[`flake8-use-pathlib`\] Make `PTH100` fix unsafe because it can change behavior ([#20100](https://github.com/astral-sh/ruff/pull/20100))
+
+### Bug fixes
+
+- \[`pyflakes`, `pylint`\] Fix false positives caused by `__class__` cell handling (`F841`, `PLE0117`) ([#20048](https://github.com/astral-sh/ruff/pull/20048))
+- \[`pyflakes`\] Fix `allowed-unused-imports` matching for top-level modules (`F401`) ([#20115](https://github.com/astral-sh/ruff/pull/20115))
+- \[`ruff`\] Fix false positive for t-strings in `default-factory-kwarg` (`RUF026`) ([#20032](https://github.com/astral-sh/ruff/pull/20032))
+- \[`ruff`\] Preserve relative whitespace in multi-line expressions (`RUF033`) ([#19647](https://github.com/astral-sh/ruff/pull/19647))
+
+### Rule changes
+
+- \[`ruff`\] Handle empty t-strings in `unnecessary-empty-iterable-within-deque-call` (`RUF037`) ([#20045](https://github.com/astral-sh/ruff/pull/20045))
+
+### Documentation
+
+- Fix incorrect `D413` links in docstrings convention FAQ ([#20089](https://github.com/astral-sh/ruff/pull/20089))
+- \[`flake8-use-pathlib`\] Update links to the table showing the correspondence between `os` and `pathlib` ([#20103](https://github.com/astral-sh/ruff/pull/20103))
+
+## 0.12.10
+
+### Preview features
+
+- \[`flake8-simplify`\] Implement fix for `maxsplit` without separator (`SIM905`) ([#19851](https://github.com/astral-sh/ruff/pull/19851))
+- \[`flake8-use-pathlib`\] Add fixes for `PTH102` and `PTH103` ([#19514](https://github.com/astral-sh/ruff/pull/19514))
+
+### Bug fixes
+
+- \[`isort`\] Handle multiple continuation lines after module docstring (`I002`) ([#19818](https://github.com/astral-sh/ruff/pull/19818))
+- \[`pyupgrade`\] Avoid reporting `__future__` features as unnecessary when they are used (`UP010`) ([#19769](https://github.com/astral-sh/ruff/pull/19769))
+- \[`pyupgrade`\] Handle nested `Optional`s (`UP045`) ([#19770](https://github.com/astral-sh/ruff/pull/19770))
+
+### Rule changes
+
+- \[`pycodestyle`\] Make `E731` fix unsafe instead of display-only for class assignments ([#19700](https://github.com/astral-sh/ruff/pull/19700))
+- \[`pyflakes`\] Add secondary annotation showing previous definition (`F811`) ([#19900](https://github.com/astral-sh/ruff/pull/19900))
+
+### Documentation
+
+- Fix description of global config file discovery strategy ([#19188](https://github.com/astral-sh/ruff/pull/19188))
+- Update outdated links to <https://typing.python.org/en/latest/source/stubs.html> ([#19992](https://github.com/astral-sh/ruff/pull/19992))
+- \[`flake8-annotations`\] Remove unused import in example (`ANN401`) ([#20000](https://github.com/astral-sh/ruff/pull/20000))
+
+## 0.12.9
+
+### Preview features
+
+- \[`airflow`\] Add check for `airflow.secrets.cache.SecretCache` (`AIR301`) ([#17707](https://github.com/astral-sh/ruff/pull/17707))
+- \[`ruff`\] Offer a safe fix for multi-digit zeros (`RUF064`) ([#19847](https://github.com/astral-sh/ruff/pull/19847))
+
+### Bug fixes
+
+- \[`flake8-blind-except`\] Fix `BLE001` false-positive on `raise ... from None` ([#19755](https://github.com/astral-sh/ruff/pull/19755))
+- \[`flake8-comprehensions`\] Fix false positive for `C420` with attribute, subscript, or slice assignment targets ([#19513](https://github.com/astral-sh/ruff/pull/19513))
+- \[`flake8-simplify`\] Fix handling of U+001C..U+001F whitespace (`SIM905`) ([#19849](https://github.com/astral-sh/ruff/pull/19849))
+
+### Rule changes
+
+- \[`pylint`\] Use lowercase hex characters to match the formatter (`PLE2513`) ([#19808](https://github.com/astral-sh/ruff/pull/19808))
+
+### Documentation
+
+- Fix `lint.future-annotations` link ([#19876](https://github.com/astral-sh/ruff/pull/19876))
+
+### Other changes
+
+- Build `riscv64` binaries for release ([#19819](https://github.com/astral-sh/ruff/pull/19819))
+
+- Add rule code to error description in GitLab output ([#19896](https://github.com/astral-sh/ruff/pull/19896))
+
+- Improve rendering of the `full` output format ([#19415](https://github.com/astral-sh/ruff/pull/19415))
+
+    Below is an example diff for [`F401`](https://docs.astral.sh/ruff/rules/unused-import/):
+
+    ```diff
+    -unused.py:8:19: F401 [*] `pathlib` imported but unused
+    +F401 [*] `pathlib` imported but unused
+    +  --> unused.py:8:19
+        |
+      7 | # Unused, _not_ marked as required (due to the alias).
+      8 | import pathlib as non_alias
+    -   |                   ^^^^^^^^^ F401
+    +   |                   ^^^^^^^^^
+      9 |
+     10 | # Unused, marked as required.
+        |
+    -   = help: Remove unused import: `pathlib`
+    +help: Remove unused import: `pathlib`
+    ```
+
+    For now, the primary difference is the movement of the filename, line number, and column information to a second line in the header. This new representation will allow us to make further additions to Ruff's diagnostics, such as adding sub-diagnostics and multiple annotations to the same snippet.
+
 ## 0.12.8

 ### Preview features
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -128,9 +128,9 @@ dependencies = [

 [[package]]
 name = "anyhow"
-version = "1.0.98"
+version = "1.0.99"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e16d2d3311acee920a9eb8d33b8cbc1787ce4a264e85f964c2404b969bdcd487"
+checksum = "b0674a1ddeecb70197781e945de4b3b8ffb61fa939a5597bcf48503737663100"

 [[package]]
 name = "approx"
@@ -257,9 +257,9 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"

 [[package]]
 name = "bitflags"
-version = "2.9.1"
+version = "2.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1b8e56985ec62d17e9c1001dc89c88ecd7dc08e47eba5ec7c29c7b5eeecde967"
+checksum = "34efbcccd345379ca2868b2b2c9d3782e9cc58ba87bc7d79d5b53d9c9ae6f25d"

 [[package]]
 name = "bitvec"
@@ -295,7 +295,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "234113d19d0d7d613b40e86fb654acf958910802bcceab913a4f9e7cda03b1a4"
 dependencies = [
 "memchr",
- "regex-automata 0.4.9",
+ "regex-automata 0.4.10",
 "serde",
 ]

@@ -322,9 +322,9 @@ dependencies = [

 [[package]]
 name = "camino"
-version = "1.1.10"
+version = "1.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0da45bc31171d8d6960122e222a67740df867c1dd53b4d51caa297084c185cab"
+checksum = "5d07aa9a93b00c76f71bc35d598bed923f6d4f3a9ca5c24b7737ae1a292841c0"
 dependencies = [
 "serde",
 ]
@@ -408,9 +408,9 @@ dependencies = [

 [[package]]
 name = "clap"
-version = "4.5.43"
+version = "4.5.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "50fd97c9dc2399518aa331917ac6f274280ec5eb34e555dd291899745c48ec6f"
+checksum = "1fc0e74a703892159f5ae7d3aac52c8e6c392f5ae5f359c70b5881d60aaac318"
 dependencies = [
 "clap_builder",
 "clap_derive",
@@ -418,9 +418,9 @@ dependencies = [

 [[package]]
 name = "clap_builder"
-version = "4.5.43"
+version = "4.5.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c35b5830294e1fa0462034af85cc95225a4cb07092c088c55bda3147cfcd8f65"
+checksum = "b3e7f4214277f3c7aa526a59dd3fbe306a370daee1f8b7b8c987069cd8e888a8"
 dependencies = [
 "anstream",
 "anstyle",
@@ -461,9 +461,9 @@ dependencies = [

 [[package]]
 name = "clap_derive"
-version = "4.5.41"
+version = "4.5.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef4f52386a59ca4c860f7393bcf8abd8dfd91ecccc0f774635ff68e92eeef491"
+checksum = "14cb31bb0a7d536caef2639baa7fad459e15c3144efefa6dbd1c84562c4739f6"
 dependencies = [
 "heck",
 "proc-macro2",
@@ -485,7 +485,7 @@ checksum = "85a8ab73a1c02b0c15597b22e09c7dc36e63b2f601f9d1e83ac0c3decd38b1ae"
 dependencies = [
 "nix 0.29.0",
 "terminfo",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "which",
 "windows-sys 0.59.0",
 ]
@@ -955,7 +955,7 @@ dependencies = [
 "libc",
 "option-ext",
 "redox_users",
- "windows-sys 0.60.2",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -1035,7 +1035,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "778e2ac28f6c47af28e4907f13ffd1e1ddbd400980a9abd7c8df189bf578a5ad"
 dependencies = [
 "libc",
- "windows-sys 0.60.2",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -1084,14 +1084,14 @@ dependencies = [

 [[package]]
 name = "filetime"
-version = "0.2.25"
+version = "0.2.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "35c0522e981e68cbfa8c3f978441a5f34b30b96e146b33cd3359176b50fe8586"
+checksum = "bc0505cd1b6fa6580283f6bdf70a73fcf4aba1184038c90902b92b3dd0df63ed"
 dependencies = [
 "cfg-if",
 "libc",
 "libredox",
- "windows-sys 0.59.0",
+ "windows-sys 0.60.2",
 ]

 [[package]]
@@ -1118,9 +1118,9 @@ checksum = "d9c4f5dac5e15c24eb999c26181a6ca40b39fe946cbe4c263c7209467bc83af2"

 [[package]]
 name = "form_urlencoded"
-version = "1.2.1"
+version = "1.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e13624c2627564efccf4934284bdd98cbaa14e79b0b5a141218e507b3a823456"
+checksum = "cb4cb245038516f5f85277875cdaa4f7d2c9a0fa0468de06ed190163b1581fcf"
 dependencies = [
 "percent-encoding",
 ]
@@ -1178,7 +1178,7 @@ checksum = "5697765925a05c9d401dd04a93dfd662d336cc25fdcc3301220385a1ffcfdde5"
 dependencies = [
 "compact_str",
 "get-size-derive2",
- "hashbrown 0.15.4",
+ "hashbrown 0.15.5",
 "smallvec",
 ]

@@ -1218,9 +1218,9 @@ dependencies = [

 [[package]]
 name = "glob"
-version = "0.3.2"
+version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a8d1add55171497b4705a648c6b583acafb01d58050a51727785f0b2c8e0a2b2"
+checksum = "0cc23270f6e1808e30a928bdc84dea0b9b4136a8bc82338574f23baf47bbd280"

 [[package]]
 name = "globset"
@@ -1231,7 +1231,7 @@ dependencies = [
 "aho-corasick",
 "bstr",
 "log",
- "regex-automata 0.4.9",
+ "regex-automata 0.4.10",
 "regex-syntax 0.8.5",
 ]

@@ -1241,7 +1241,7 @@ version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0bf760ebf69878d9fd8f110c89703d90ce35095324d1f1edcb595c63945ee757"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "ignore",
 "walkdir",
 ]
@@ -1264,9 +1264,9 @@ checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"

 [[package]]
 name = "hashbrown"
-version = "0.15.4"
+version = "0.15.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5971ac85611da7067dbfcabef3c70ebb5606018acd9e2a3903a0da507521e0d5"
+checksum = "9229cfe53dfd69f0609a49f65461bd93001ea1ef889cd5529dd176593f5338a1"
 dependencies = [
 "allocator-api2",
 "equivalent",
@@ -1279,7 +1279,7 @@ version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7382cf6263419f2d8df38c55d7da83da5c18aef87fc7a7fc1fb1e344edfe14c1"
 dependencies = [
- "hashbrown 0.15.4",
+ "hashbrown 0.15.5",
 ]

 [[package]]
@@ -1430,9 +1430,9 @@ checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"

 [[package]]
 name = "idna"
-version = "1.0.3"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "686f825264d630750a544639377bae737628043f20d38bbc029e8f29ea968a7e"
+checksum = "3b0875f23caa03898994f6ddc501886a45c7d3d62d04d2d90788d47be1b1e4de"
 dependencies = [
 "idna_adapter",
 "smallvec",
@@ -1459,7 +1459,7 @@ dependencies = [
 "globset",
 "log",
 "memchr",
- "regex-automata 0.4.9",
+ "regex-automata 0.4.10",
 "same-file",
 "walkdir",
 "winapi-util",
@@ -1471,7 +1471,7 @@ version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "17d34b7d42178945f775e84bc4c36dde7c1c6cdfea656d3354d009056f2bb3d2"
 dependencies = [
- "hashbrown 0.15.4",
+ "hashbrown 0.15.5",
 ]

 [[package]]
@@ -1486,12 +1486,12 @@ dependencies = [

 [[package]]
 name = "indexmap"
-version = "2.10.0"
+version = "2.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fe4cd85333e22411419a0bcae1297d25e58c9443848b11dc6a86fefe8c78a661"
+checksum = "f2481980430f9f78649238835720ddccc57e52df14ffce1c6f37391d61b563e9"
 dependencies = [
 "equivalent",
- "hashbrown 0.15.4",
+ "hashbrown 0.15.5",
 "serde",
 ]

@@ -1521,7 +1521,7 @@ version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f37dccff2791ab604f9babef0ba14fbe0be30bd368dc541e2b08d07c8aa908f3"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "inotify-sys",
 "libc",
 ]
@@ -1764,9 +1764,9 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"

 [[package]]
 name = "libc"
-version = "0.2.174"
+version = "0.2.175"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1171693293099992e19cddea4e8b849964e9846f4acee11b3948bcc337be8776"
+checksum = "6a82ae493e598baaea5209805c49bbf2ea7de956d50d7da0da1164f9c6d28543"

 [[package]]
 name = "libcst"
@@ -1780,7 +1780,7 @@ dependencies = [
 "paste",
 "peg",
 "regex",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 ]

 [[package]]
@@ -1809,7 +1809,7 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "391290121bad3d37fbddad76d8f5d1c1c314cfc646d143d7e07a3086ddff0ce3"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "libc",
 "redox_syscall",
 ]
@@ -2014,7 +2014,7 @@ version = "0.29.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "71e2746dc3a24dd78b3cfcb7be93368c6de9963d30f43a6a73998a9cf4b17b46"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "cfg-if",
 "cfg_aliases",
 "libc",
@@ -2026,7 +2026,7 @@ version = "0.30.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "74523f3a35e05aba87a1d978330aef40f67b0304ac79c1c00b294c9830543db6"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "cfg-if",
 "cfg_aliases",
 "libc",
@@ -2054,7 +2054,7 @@ version = "8.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4d3d07927151ff8575b7087f245456e549fea62edf0ec4e565a5ee50c8402bc3"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "fsevent-sys",
 "inotify",
 "kqueue",
@@ -2127,9 +2127,9 @@ checksum = "04744f49eae99ab78e0d5c0b603ab218f515ea8cfe5a456d7629ad883a3b6e7d"

 [[package]]
 name = "ordermap"
-version = "0.5.8"
+version = "0.5.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d6bff06e4a5dc6416bead102d3e63c480dd852ffbb278bf8cfeb4966b329609"
+checksum = "2fd6fedcd996c8c97932075cc3811d83f53280f48d5620e4e3cab7f6a12678c4"
 dependencies = [
 "indexmap",
 "serde",
@@ -2283,9 +2283,9 @@ dependencies = [

 [[package]]
 name = "percent-encoding"
-version = "2.3.1"
+version = "2.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
+checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"

 [[package]]
 name = "pest"
@@ -2294,7 +2294,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1db05f56d34358a8b1066f67cbb203ee3e7ed2ba674a6263a1d5ec6db2204323"
 dependencies = [
 "memchr",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "ucd-trie",
 ]

@@ -2473,9 +2473,9 @@ dependencies = [

 [[package]]
 name = "proc-macro2"
-version = "1.0.95"
+version = "1.0.101"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "02b3e5e68a3a1a02aad3ec490a98007cbc13c37cbe84a3cd7b8e406d76e7f778"
+checksum = "89ae43fd86e4158d6db51ad8e2b80f313af9cc74f5c0e03ccb87de09998732de"
 dependencies = [
 "unicode-ident",
 ]
@@ -2490,7 +2490,7 @@ dependencies = [
 "pep440_rs",
 "pep508_rs",
 "serde",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "toml 0.8.23",
 ]

@@ -2505,7 +2505,7 @@ dependencies = [
 "newtype-uuid",
 "quick-xml",
 "strip-ansi-escapes",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "uuid",
 ]

@@ -2666,7 +2666,7 @@ version = "0.5.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5407465600fb0548f1442edf71dd20683c6ed326200ace4b1ef0763521bb3b77"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 ]

 [[package]]
@@ -2677,18 +2677,18 @@ checksum = "a4e608c6638b9c18977b00b475ac1f28d14e84b27d8d42f70e0bf1e3dec127ac"
 dependencies = [
 "getrandom 0.2.16",
 "libredox",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 ]

 [[package]]
 name = "regex"
-version = "1.11.1"
+version = "1.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b544ef1b4eac5dc2db33ea63606ae9ffcfac26c1416a2806ae0bf5f56b201191"
+checksum = "23d7fd106d8c02486a8d64e778353d1cffe08ce79ac2e82f540c86d0facf6912"
 dependencies = [
 "aho-corasick",
 "memchr",
- "regex-automata 0.4.9",
+ "regex-automata 0.4.10",
 "regex-syntax 0.8.5",
 ]

@@ -2703,9 +2703,9 @@ dependencies = [

 [[package]]
 name = "regex-automata"
-version = "0.4.9"
+version = "0.4.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "809e8dc61f6de73b46c85f4c96486310fe304c434cfa43669d7b40f711150908"
+checksum = "6b9458fa0bfeeac22b5ca447c63aaf45f28439a709ccd244698632f9aa6394d6"
 dependencies = [
 "aho-corasick",
 "memchr",
@@ -2743,13 +2743,13 @@ dependencies = [

 [[package]]
 name = "ruff"
-version = "0.12.8"
+version = "0.12.11"
 dependencies = [
 "anyhow",
 "argfile",
 "assert_fs",
 "bincode 2.0.1",
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "cachedir",
 "clap",
 "clap_complete_command",
@@ -2793,7 +2793,7 @@ dependencies = [
 "strum",
 "tempfile",
 "test-case",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "tikv-jemallocator",
 "toml 0.9.5",
 "tracing",
@@ -2870,6 +2870,7 @@ dependencies = [
 "insta",
 "matchit",
 "path-slash",
+ "pathdiff",
 "quick-junit",
 "ruff_annotate_snippets",
 "ruff_cache",
@@ -2886,8 +2887,9 @@ dependencies = [
 "schemars",
 "serde",
 "serde_json",
+ "similar",
 "tempfile",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "tracing",
 "tracing-subscriber",
 "ty_static",
@@ -2934,6 +2936,7 @@ dependencies = [
 "tracing-subscriber",
 "ty",
 "ty_project",
+ "ty_python_semantic",
 "ty_static",
 "url",
 ]
@@ -2996,17 +2999,17 @@ dependencies = [

 [[package]]
 name = "ruff_linter"
-version = "0.12.8"
+version = "0.12.11"
 dependencies = [
 "aho-corasick",
 "anyhow",
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "clap",
 "colored 3.0.0",
 "fern",
 "glob",
 "globset",
- "hashbrown 0.15.4",
+ "hashbrown 0.15.5",
 "imperative",
 "insta",
 "is-macro",
@@ -3018,11 +3021,9 @@ dependencies = [
 "memchr",
 "natord",
 "path-absolutize",
- "pathdiff",
 "pep440_rs",
 "pyproject-toml",
 "regex",
- "ruff_annotate_snippets",
 "ruff_cache",
 "ruff_db",
 "ruff_diagnostics",
@@ -3048,7 +3049,7 @@ dependencies = [
 "strum_macros",
 "tempfile",
 "test-case",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "toml 0.9.5",
 "typed-arena",
 "unicode-normalization",
@@ -3074,6 +3075,7 @@ name = "ruff_memory_usage"
 version = "0.0.0"
 dependencies = [
 "get-size2",
+ "ordermap",
 ]

 [[package]]
@@ -3090,7 +3092,7 @@ dependencies = [
 "serde_json",
 "serde_with",
 "test-case",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "uuid",
 ]

@@ -3106,7 +3108,7 @@ name = "ruff_python_ast"
 version = "0.0.0"
 dependencies = [
 "aho-corasick",
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "compact_str",
 "get-size2",
 "is-macro",
@@ -3121,7 +3123,7 @@ dependencies = [
 "salsa",
 "schemars",
 "serde",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 ]

 [[package]]
@@ -3175,7 +3177,7 @@ dependencies = [
 "similar",
 "smallvec",
 "static_assertions",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "tracing",
 ]

@@ -3194,7 +3196,7 @@ dependencies = [
 name = "ruff_python_literal"
 version = "0.0.0"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "itertools 0.14.0",
 "ruff_python_ast",
 "unic-ucd-category",
@@ -3205,7 +3207,7 @@ name = "ruff_python_parser"
 version = "0.0.0"
 dependencies = [
 "anyhow",
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "bstr",
 "compact_str",
 "get-size2",
@@ -3230,7 +3232,7 @@ dependencies = [
 name = "ruff_python_semantic"
 version = "0.0.0"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "insta",
 "is-macro",
 "ruff_cache",
@@ -3251,7 +3253,7 @@ dependencies = [
 name = "ruff_python_stdlib"
 version = "0.0.0"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "unicode-ident",
 ]

@@ -3305,7 +3307,7 @@ dependencies = [
 "serde",
 "serde_json",
 "shellexpand",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "toml 0.9.5",
 "tracing",
 "tracing-log",
@@ -3335,7 +3337,7 @@ dependencies = [

 [[package]]
 name = "ruff_wasm"
-version = "0.12.8"
+version = "0.12.11"
 dependencies = [
 "console_error_panic_hook",
 "console_log",
@@ -3428,11 +3430,11 @@ version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "11181fbabf243db407ef8df94a6ce0b2f9a733bd8be4ad02b4eda9602296cac8"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "errno",
 "libc",
 "linux-raw-sys",
- "windows-sys 0.60.2",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -3450,13 +3452,13 @@ checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 [[package]]
 name = "salsa"
 version = "0.23.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=b121ee46c4483ba74c19e933a3522bd548eb7343#b121ee46c4483ba74c19e933a3522bd548eb7343"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=a3ffa22cb26756473d56f867aedec3fd907c4dd9#a3ffa22cb26756473d56f867aedec3fd907c4dd9"
 dependencies = [
 "boxcar",
 "compact_str",
 "crossbeam-queue",
 "crossbeam-utils",
- "hashbrown 0.15.4",
+ "hashbrown 0.15.5",
 "hashlink",
 "indexmap",
 "intrusive-collections",
@@ -3474,12 +3476,12 @@ dependencies = [
 [[package]]
 name = "salsa-macro-rules"
 version = "0.23.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=b121ee46c4483ba74c19e933a3522bd548eb7343#b121ee46c4483ba74c19e933a3522bd548eb7343"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=a3ffa22cb26756473d56f867aedec3fd907c4dd9#a3ffa22cb26756473d56f867aedec3fd907c4dd9"

 [[package]]
 name = "salsa-macros"
 version = "0.23.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=b121ee46c4483ba74c19e933a3522bd548eb7343#b121ee46c4483ba74c19e933a3522bd548eb7343"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=a3ffa22cb26756473d56f867aedec3fd907c4dd9#a3ffa22cb26756473d56f867aedec3fd907c4dd9"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -3576,9 +3578,9 @@ dependencies = [

 [[package]]
 name = "serde_json"
-version = "1.0.142"
+version = "1.0.143"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "030fedb782600dcbd6f02d479bf0d817ac3bb40d644745b769d6a96bc3afc5a7"
+checksum = "d401abef1d108fbd9cbaebc3e46611f4b1021f714a0597a71f41ee463f5f4a5a"
 dependencies = [
 "itoa",
 "memchr",
@@ -3789,9 +3791,9 @@ dependencies = [

 [[package]]
 name = "syn"
-version = "2.0.104"
+version = "2.0.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "17b6f705963418cdb9927482fa304bc562ece2fdd4f616084c50b7023b435a40"
+checksum = "ede7c438028d4436d71104916910f5bb611972c5cfd7f89b8300a8186e6fada6"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -3915,11 +3917,11 @@ dependencies = [

 [[package]]
 name = "thiserror"
-version = "2.0.12"
+version = "2.0.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "567b8a2dae586314f7be2a752ec7474332959c6460e02bde30d702a66d488708"
+checksum = "3467d614147380f2e4e374161426ff399c91084acd2363eaf549172b3d5e60c0"
 dependencies = [
- "thiserror-impl 2.0.12",
+ "thiserror-impl 2.0.16",
 ]

 [[package]]
@@ -3935,9 +3937,9 @@ dependencies = [

 [[package]]
 name = "thiserror-impl"
-version = "2.0.12"
+version = "2.0.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f7cf42b4507d8ea322120659672cf1b9dbb93f8f2d4ecfd6e51350ff5b17a1d"
+checksum = "6c5e1be1c48b9172ee610da68fd9cd2770e7a4056cb3fc98710ee6906f0c7960"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -4136,9 +4138,9 @@ dependencies = [

 [[package]]
 name = "tracing-indicatif"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e1983afead46ff13a3c93581e0cec31d20b29efdd22cbdaa8b9f850eccf2c352"
+checksum = "04d4e11e0e27acef25a47f27e9435355fecdc488867fa2bc90e75b0700d2823d"
 dependencies = [
 "indicatif",
 "tracing",
@@ -4238,17 +4240,22 @@ dependencies = [
 name = "ty_ide"
 version = "0.0.0"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
+ "get-size2",
 "insta",
 "itertools 0.14.0",
+ "rayon",
 "regex",
 "ruff_db",
+ "ruff_index",
+ "ruff_memory_usage",
 "ruff_python_ast",
 "ruff_python_parser",
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
 "rustc-hash",
+ "salsa",
 "smallvec",
 "tracing",
 "ty_project",
@@ -4271,7 +4278,7 @@ dependencies = [
 "pep440_rs",
 "rayon",
 "regex",
- "regex-automata 0.4.9",
+ "regex-automata 0.4.10",
 "ruff_cache",
 "ruff_db",
 "ruff_macros",
@@ -4284,7 +4291,7 @@ dependencies = [
 "salsa",
 "schemars",
 "serde",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "toml 0.9.5",
 "tracing",
 "ty_combine",
@@ -4297,7 +4304,7 @@ name = "ty_python_semantic"
 version = "0.0.0"
 dependencies = [
 "anyhow",
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "bitvec",
 "camino",
 "colored 3.0.0",
@@ -4306,7 +4313,7 @@ dependencies = [
 "drop_bomb",
 "get-size2",
 "glob",
- "hashbrown 0.15.4",
+ "hashbrown 0.15.5",
 "indexmap",
 "insta",
 "itertools 0.14.0",
@@ -4337,7 +4344,7 @@ dependencies = [
 "strum_macros",
 "tempfile",
 "test-case",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "tracing",
 "ty_python_semantic",
 "ty_static",
@@ -4350,7 +4357,7 @@ name = "ty_server"
 version = "0.0.0"
 dependencies = [
 "anyhow",
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "crossbeam",
 "dunce",
 "insta",
@@ -4371,7 +4378,7 @@ dependencies = [
 "serde_json",
 "shellexpand",
 "tempfile",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "tracing",
 "tracing-subscriber",
 "ty_combine",
@@ -4393,7 +4400,7 @@ name = "ty_test"
 version = "0.0.0"
 dependencies = [
 "anyhow",
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 "camino",
 "colored 3.0.0",
 "insta",
@@ -4412,7 +4419,7 @@ dependencies = [
 "serde",
 "smallvec",
 "tempfile",
- "thiserror 2.0.12",
+ "thiserror 2.0.16",
 "toml 0.9.5",
 "tracing",
 "ty_python_semantic",
@@ -4589,9 +4596,9 @@ checksum = "6d49784317cd0d1ee7ec5c716dd598ec5b4483ea832a2dced265471cc0f690ae"

 [[package]]
 name = "url"
-version = "2.5.4"
+version = "2.5.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32f8b686cadd1473f4bd0117a5d28d36b1ade384ea9b5069a1c40aefed7fda60"
+checksum = "08bc136a29a3d1758e07a9cca267be308aeebf5cfd5a10f3f67ab2097683ef5b"
 dependencies = [
 "form_urlencoded",
 "idna",
@@ -5143,7 +5150,7 @@ version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6f42320e61fe2cfd34354ecb597f86f413484a798ba44a8ca1165c58d42da6c1"
 dependencies = [
- "bitflags 2.9.1",
+ "bitflags 2.9.3",
 ]

 [[package]]
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,7 @@ resolver = "2"
 [workspace.package]
 # Please update rustfmt.toml when bumping the Rust edition
 edition = "2024"
-rust-version = "1.86"
+rust-version = "1.87"
 homepage = "https://docs.astral.sh/ruff"
 documentation = "https://docs.astral.sh/ruff"
 repository = "https://github.com/astral-sh/ruff"
@@ -143,7 +143,7 @@ regex-automata = { version = "0.4.9" }
 rustc-hash = { version = "2.0.0" }
 rustc-stable-hash = { version = "0.1.2" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "b121ee46c4483ba74c19e933a3522bd548eb7343", default-features = false, features = [
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "a3ffa22cb26756473d56f867aedec3fd907c4dd9", default-features = false, features = [
    "compact_str",
    "macros",
    "salsa_unstable",
@@ -215,6 +215,8 @@ unexpected_cfgs = { level = "warn", check-cfg = [

 [workspace.lints.clippy]
 pedantic = { level = "warn", priority = -2 }
+# Enabled at the crate level
+disallowed_methods = "allow"
 # Allowed pedantic lints
 char_lit_as_u8 = "allow"
 collapsible_else_if = "allow"
@@ -253,6 +255,7 @@ unused_peekable = "warn"
 # Diagnostics are not actionable: Enable once https://github.com/rust-lang/rust-clippy/issues/13774 is resolved.
 large_stack_arrays = "allow"

+
 [profile.release]
 # Note that we set these explicitly, and these values
 # were chosen based on a trade-off between compile times
--- a/README.md
+++ b/README.md
@@ -148,8 +148,8 @@ curl -LsSf https://astral.sh/ruff/install.sh | sh
 powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"

 # For a specific version.
-curl -LsSf https://astral.sh/ruff/0.12.8/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.12.8/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.12.11/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.12.11/install.ps1 | iex"
 ```

 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -182,7 +182,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
  # Ruff version.
-  rev: v0.12.8
+  rev: v0.12.11
  hooks:
    # Run the linter.
    - id: ruff-check
--- a/clippy.toml
+++ b/clippy.toml
@@ -24,3 +24,20 @@ ignore-interior-mutability = [
    # The expression is read-only.
    "ruff_python_ast::hashable::HashableExpr",
 ]
+
+disallowed-methods = [
+    { path = "std::env::var", reason = "Use System::env_var instead in ty crates" },
+    { path = "std::env::current_dir", reason = "Use System::current_directory instead in ty crates" },
+    { path = "std::fs::read_to_string", reason = "Use System::read_to_string instead in ty crates" },
+    { path = "std::fs::metadata", reason = "Use System::path_metadata instead in ty crates" },
+    { path = "std::fs::canonicalize", reason = "Use System::canonicalize_path instead in ty crates" },
+    { path = "dunce::canonicalize", reason = "Use System::canonicalize_path instead in ty crates" },
+    { path = "std::fs::read_dir", reason = "Use System::read_directory instead in ty crates" },
+    { path = "std::fs::write", reason = "Use WritableSystem::write_file instead in ty crates" },
+    { path = "std::fs::create_dir_all", reason = "Use WritableSystem::create_directory_all instead in ty crates" },
+    { path = "std::fs::File::create_new", reason = "Use WritableSystem::create_new_file instead in ty crates" },
+    # Path methods that have System trait equivalents
+    { path = "std::path::Path::exists", reason = "Use System::path_exists instead in ty crates" },
+    { path = "std::path::Path::is_dir", reason = "Use System::is_directory instead in ty crates" },
+    { path = "std::path::Path::is_file", reason = "Use System::is_file instead in ty crates" },
+]
--- a/crates/ruff/Cargo.toml
+++ b/crates/ruff/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.12.8"
+version = "0.12.11"
 publish = true
 authors = { workspace = true }
 edition = { workspace = true }
@@ -85,7 +85,7 @@ dist = true
 [target.'cfg(target_os = "windows")'.dependencies]
 mimalloc = { workspace = true }

-[target.'cfg(all(not(target_os = "windows"), not(target_os = "openbsd"), not(target_os = "aix"), not(target_os = "android"), any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "powerpc64")))'.dependencies]
+[target.'cfg(all(not(target_os = "windows"), not(target_os = "openbsd"), not(target_os = "aix"), not(target_os = "android"), any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "powerpc64", target_arch = "riscv64")))'.dependencies]
 tikv-jemallocator = { workspace = true }

 [lints]
--- a/crates/ruff/src/cache.rs
+++ b/crates/ruff/src/cache.rs
@@ -13,25 +13,16 @@ use itertools::Itertools;
 use log::{debug, error};
 use rayon::iter::ParallelIterator;
 use rayon::iter::{IntoParallelIterator, ParallelBridge};
-use ruff_linter::codes::Rule;
 use rustc_hash::FxHashMap;
 use tempfile::NamedTempFile;

 use ruff_cache::{CacheKey, CacheKeyHasher};
-use ruff_db::diagnostic::Diagnostic;
-use ruff_diagnostics::Fix;
-use ruff_linter::message::create_lint_diagnostic;
 use ruff_linter::package::PackageRoot;
 use ruff_linter::{VERSION, warn_user};
 use ruff_macros::CacheKey;
-use ruff_notebook::NotebookIndex;
-use ruff_source_file::SourceFileBuilder;
-use ruff_text_size::{TextRange, TextSize};
 use ruff_workspace::Settings;
 use ruff_workspace::resolver::Resolver;

-use crate::diagnostics::Diagnostics;
-
 /// [`Path`] that is relative to the package root in [`PackageCache`].
 pub(crate) type RelativePath = Path;
 /// [`PathBuf`] that is relative to the package root in [`PackageCache`].
@@ -298,13 +289,8 @@ impl Cache {
        });
    }

-    pub(crate) fn update_lint(
-        &self,
-        path: RelativePathBuf,
-        key: &FileCacheKey,
-        data: LintCacheData,
-    ) {
-        self.update(path, key, ChangeData::Lint(data));
+    pub(crate) fn set_linted(&self, path: RelativePathBuf, key: &FileCacheKey, yes: bool) {
+        self.update(path, key, ChangeData::Linted(yes));
    }

    pub(crate) fn set_formatted(&self, path: RelativePathBuf, key: &FileCacheKey) {
@@ -339,42 +325,15 @@ pub(crate) struct FileCache {
 }

 impl FileCache {
-    /// Convert the file cache into `Diagnostics`, using `path` as file name.
-    pub(crate) fn to_diagnostics(&self, path: &Path) -> Option<Diagnostics> {
-        self.data.lint.as_ref().map(|lint| {
-            let diagnostics = if lint.messages.is_empty() {
-                Vec::new()
-            } else {
-                let file = SourceFileBuilder::new(path.to_string_lossy(), &*lint.source).finish();
-                lint.messages
-                    .iter()
-                    .map(|msg| {
-                        create_lint_diagnostic(
-                            &msg.body,
-                            msg.suggestion.as_ref(),
-                            msg.range,
-                            msg.fix.clone(),
-                            msg.parent,
-                            file.clone(),
-                            msg.noqa_offset,
-                            msg.rule,
-                        )
-                    })
-                    .collect()
-            };
-            let notebook_indexes = if let Some(notebook_index) = lint.notebook_index.as_ref() {
-                FxHashMap::from_iter([(path.to_string_lossy().to_string(), notebook_index.clone())])
-            } else {
-                FxHashMap::default()
-            };
-            Diagnostics::new(diagnostics, notebook_indexes)
-        })
+    /// Return whether or not the file in the cache was linted and found to have no diagnostics.
+    pub(crate) fn linted(&self) -> bool {
+        self.data.linted
    }
 }

 #[derive(Debug, Default, bincode::Decode, bincode::Encode)]
 struct FileCacheData {
-    lint: Option<LintCacheData>,
+    linted: bool,
    formatted: bool,
 }

@@ -410,88 +369,6 @@ pub(crate) fn init(path: &Path) -> Result<()> {
    Ok(())
 }

-#[derive(bincode::Decode, Debug, bincode::Encode, PartialEq)]
-pub(crate) struct LintCacheData {
-    /// Imports made.
-    // pub(super) imports: ImportMap,
-    /// Diagnostic messages.
-    pub(super) messages: Vec<CacheMessage>,
-    /// Source code of the file.
-    ///
-    /// # Notes
-    ///
-    /// This will be empty if `messages` is empty.
-    pub(super) source: String,
-    /// Notebook index if this file is a Jupyter Notebook.
-    #[bincode(with_serde)]
-    pub(super) notebook_index: Option<NotebookIndex>,
-}
-
-impl LintCacheData {
-    pub(crate) fn from_diagnostics(
-        diagnostics: &[Diagnostic],
-        notebook_index: Option<NotebookIndex>,
-    ) -> Self {
-        let source = if let Some(msg) = diagnostics.first() {
-            msg.expect_ruff_source_file().source_text().to_owned()
-        } else {
-            String::new() // No messages, no need to keep the source!
-        };
-
-        let messages = diagnostics
-            .iter()
-            // Parse the kebab-case rule name into a `Rule`. This will fail for syntax errors, so
-            // this also serves to filter them out, but we shouldn't be caching files with syntax
-            // errors anyway.
-            .filter_map(|msg| Some((msg.name().parse().ok()?, msg)))
-            .map(|(rule, msg)| {
-                // Make sure that all message use the same source file.
-                assert_eq!(
-                    msg.expect_ruff_source_file(),
-                    diagnostics.first().unwrap().expect_ruff_source_file(),
-                    "message uses a different source file"
-                );
-                CacheMessage {
-                    rule,
-                    body: msg.body().to_string(),
-                    suggestion: msg.first_help_text().map(ToString::to_string),
-                    range: msg.expect_range(),
-                    parent: msg.parent(),
-                    fix: msg.fix().cloned(),
-                    noqa_offset: msg.noqa_offset(),
-                }
-            })
-            .collect();
-
-        Self {
-            messages,
-            source,
-            notebook_index,
-        }
-    }
-}
-
-/// On disk representation of a diagnostic message.
-#[derive(bincode::Decode, Debug, bincode::Encode, PartialEq)]
-pub(super) struct CacheMessage {
-    /// The rule for the cached diagnostic.
-    #[bincode(with_serde)]
-    rule: Rule,
-    /// The message body to display to the user, to explain the diagnostic.
-    body: String,
-    /// The message to display to the user, to explain the suggested fix.
-    suggestion: Option<String>,
-    /// Range into the message's [`FileCache::source`].
-    #[bincode(with_serde)]
-    range: TextRange,
-    #[bincode(with_serde)]
-    parent: Option<TextSize>,
-    #[bincode(with_serde)]
-    fix: Option<Fix>,
-    #[bincode(with_serde)]
-    noqa_offset: Option<TextSize>,
-}
-
 pub(crate) trait PackageCaches {
    fn get(&self, package_root: &Path) -> Option<&Cache>;

@@ -579,15 +456,15 @@ struct Change {

 #[derive(Debug)]
 enum ChangeData {
-    Lint(LintCacheData),
+    Linted(bool),
    Formatted,
 }

 impl ChangeData {
    fn apply(self, data: &mut FileCacheData) {
        match self {
-            ChangeData::Lint(new_lint) => {
-                data.lint = Some(new_lint);
+            ChangeData::Linted(yes) => {
+                data.linted = yes;
            }
            ChangeData::Formatted => {
                data.formatted = true;
@@ -612,7 +489,6 @@ mod tests {
    use test_case::test_case;

    use ruff_cache::CACHE_DIR_NAME;
-    use ruff_db::diagnostic::Diagnostic;
    use ruff_linter::package::PackageRoot;
    use ruff_linter::settings::LinterSettings;
    use ruff_linter::settings::flags;
@@ -620,7 +496,7 @@ mod tests {
    use ruff_python_ast::{PySourceType, PythonVersion};
    use ruff_workspace::Settings;

-    use crate::cache::{self, FileCache, FileCacheData, FileCacheKey};
+    use crate::cache::{self, ChangeData, FileCache, FileCacheData, FileCacheKey};
    use crate::cache::{Cache, RelativePathBuf};
    use crate::commands::format::{FormatCommandError, FormatMode, FormatResult, format_path};
    use crate::diagnostics::{Diagnostics, lint_path};
@@ -647,7 +523,7 @@ mod tests {
        assert_eq!(cache.changes.lock().unwrap().len(), 0);

        let mut paths = Vec::new();
-        let mut parse_errors = Vec::new();
+        let mut paths_with_diagnostics = Vec::new();
        let mut expected_diagnostics = Diagnostics::default();
        for entry in fs::read_dir(&package_root).unwrap() {
            let entry = entry.unwrap();
@@ -671,7 +547,7 @@ mod tests {
                    continue;
                }

-                let diagnostics = lint_path(
+                let mut diagnostics = lint_path(
                    &path,
                    Some(PackageRoot::root(&package_root)),
                    &settings.linter,
@@ -681,8 +557,15 @@ mod tests {
                    UnsafeFixes::Enabled,
                )
                .unwrap();
-                if diagnostics.inner.iter().any(Diagnostic::is_invalid_syntax) {
-                    parse_errors.push(path.clone());
+                if diagnostics.inner.is_empty() {
+                    // We won't load a notebook index from the cache for files without diagnostics,
+                    // so remove them from `expected_diagnostics` too. This allows us to keep the
+                    // full equality assertion below.
+                    diagnostics
+                        .notebook_indexes
+                        .remove(&path.to_string_lossy().to_string());
+                } else {
+                    paths_with_diagnostics.push(path.clone());
                }
                paths.push(path);
                expected_diagnostics += diagnostics;
@@ -695,11 +578,11 @@ mod tests {
        let cache = Cache::open(package_root.clone(), &settings);
        assert_ne!(cache.package.files.len(), 0);

-        parse_errors.sort();
+        paths_with_diagnostics.sort();

        for path in &paths {
-            if parse_errors.binary_search(path).is_ok() {
-                continue; // We don't cache parsing errors.
+            if paths_with_diagnostics.binary_search(path).is_ok() {
+                continue; // We don't cache files with diagnostics.
            }

            let relative_path = cache.relative_path(path).unwrap();
@@ -733,7 +616,7 @@ mod tests {

    #[test]
    fn cache_adds_file_on_lint() {
-        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\", \"b\"])\n";
+        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\"])\n";

        let test_cache = TestCache::new("cache_adds_file_on_lint");
        let cache = test_cache.open();
@@ -757,7 +640,7 @@ mod tests {

    #[test]
    fn cache_adds_files_on_lint() {
-        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\", \"b\"])\n";
+        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\"])\n";

        let test_cache = TestCache::new("cache_adds_files_on_lint");
        let cache = test_cache.open();
@@ -782,6 +665,40 @@ mod tests {
        cache.persist().unwrap();
    }

+    #[test]
+    fn cache_does_not_add_file_on_lint_with_diagnostic() {
+        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\", \"b\"])\n";
+
+        let test_cache = TestCache::new("cache_does_not_add_file_on_lint_with_diagnostic");
+        let cache = test_cache.open();
+        test_cache.write_source_file("source.py", source);
+        assert_eq!(cache.changes.lock().unwrap().len(), 0);
+
+        cache.persist().unwrap();
+        let cache = test_cache.open();
+
+        let results = test_cache
+            .lint_file_with_cache("source.py", &cache)
+            .expect("Failed to lint test file");
+        assert_eq!(results.inner.len(), 1, "Expected one F822 diagnostic");
+        assert_eq!(
+            cache.changes.lock().unwrap().len(),
+            1,
+            "Files with diagnostics still trigger change events"
+        );
+        assert!(
+            cache
+                .changes
+                .lock()
+                .unwrap()
+                .last()
+                .is_some_and(|change| matches!(change.new_data, ChangeData::Linted(false))),
+            "Files with diagnostics are marked as unlinted"
+        );
+
+        cache.persist().unwrap();
+    }
+
    #[test]
    fn cache_adds_files_on_format() {
        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\", \"b\"])\n";
@@ -812,7 +729,7 @@ mod tests {

    #[test]
    fn cache_invalidated_on_file_modified_time() {
-        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\", \"b\"])\n";
+        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\"])\n";

        let test_cache = TestCache::new("cache_invalidated_on_file_modified_time");
        let cache = test_cache.open();
@@ -869,7 +786,7 @@ mod tests {
            file.set_permissions(perms)
        }

-        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\", \"b\"])\n";
+        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\"])\n";

        let test_cache = TestCache::new("cache_invalidated_on_permission_change");
        let cache = test_cache.open();
@@ -922,7 +839,7 @@ mod tests {
        );

        // Now actually lint a file.
-        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\", \"b\"])\n";
+        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\"])\n";
        test_cache.write_source_file("new.py", source);
        let new_path_key = RelativePathBuf::from("new.py");
        assert_eq!(cache.changes.lock().unwrap().len(), 0);
@@ -945,7 +862,7 @@ mod tests {

    #[test]
    fn format_updates_cache_entry() {
-        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\", \"b\"])\n";
+        let source: &[u8] = b"a = 1\n\n__all__ = list([\"a\"])\n";

        let test_cache = TestCache::new("format_updates_cache_entry");
        let cache = test_cache.open();
@@ -979,7 +896,7 @@ mod tests {
            panic!("Cache entry for `source.py` is missing.");
        };

-        assert!(file_cache.data.lint.is_some());
+        assert!(file_cache.data.linted);
        assert!(file_cache.data.formatted);
    }

@@ -1029,7 +946,7 @@ mod tests {
            panic!("Cache entry for `source.py` is missing.");
        };

-        assert_eq!(file_cache.data.lint, None);
+        assert!(!file_cache.data.linted);
        assert!(file_cache.data.formatted);
    }

--- a/crates/ruff/src/diagnostics.rs
+++ b/crates/ruff/src/diagnostics.rs
@@ -20,15 +20,21 @@ use ruff_linter::settings::types::UnsafeFixes;
 use ruff_linter::settings::{LinterSettings, flags};
 use ruff_linter::source_kind::{SourceError, SourceKind};
 use ruff_linter::{IOError, Violation, fs};
-use ruff_notebook::{Notebook, NotebookError, NotebookIndex};
+use ruff_notebook::{NotebookError, NotebookIndex};
 use ruff_python_ast::{PySourceType, SourceType, TomlSourceType};
 use ruff_source_file::SourceFileBuilder;
 use ruff_text_size::TextRange;
 use ruff_workspace::Settings;
 use rustc_hash::FxHashMap;

-use crate::cache::{Cache, FileCacheKey, LintCacheData};
+use crate::cache::{Cache, FileCache, FileCacheKey};

+/// A collection of [`Diagnostic`]s and additional information needed to render them.
+///
+/// Note that `notebook_indexes` may be empty if there are no diagnostics because the
+/// `NotebookIndex` isn't cached in this case. This isn't a problem for any current uses as of
+/// 2025-08-12, which are all related to diagnostic rendering, but could be surprising if used
+/// differently in the future.
 #[derive(Debug, Default, PartialEq)]
 pub(crate) struct Diagnostics {
    pub(crate) inner: Vec<Diagnostic>,
@@ -193,19 +199,9 @@ pub(crate) fn lint_path(
            let cache_key = FileCacheKey::from_path(path).context("Failed to create cache key")?;
            let cached_diagnostics = cache
                .get(relative_path, &cache_key)
-                .and_then(|entry| entry.to_diagnostics(path));
-            if let Some(diagnostics) = cached_diagnostics {
-                // `FixMode::Generate` and `FixMode::Diff` rely on side-effects (writing to disk,
-                // and writing the diff to stdout, respectively). If a file has diagnostics, we
-                // need to avoid reading from and writing to the cache in these modes.
-                if match fix_mode {
-                    flags::FixMode::Generate => true,
-                    flags::FixMode::Apply | flags::FixMode::Diff => {
-                        diagnostics.inner.is_empty() && diagnostics.fixed.is_empty()
-                    }
-                } {
-                    return Ok(diagnostics);
-                }
+                .is_some_and(FileCache::linted);
+            if cached_diagnostics {
+                return Ok(Diagnostics::default());
            }

            // Stash the file metadata for later so when we update the cache it reflects the prerun
@@ -322,31 +318,21 @@ pub(crate) fn lint_path(
            (result, transformed, fixed)
        };

-    let has_error = result.has_syntax_errors();
    let diagnostics = result.diagnostics;

    if let Some((cache, relative_path, key)) = caching {
-        // We don't cache parsing errors.
-        if !has_error {
-            // `FixMode::Apply` and `FixMode::Diff` rely on side-effects (writing to disk,
-            // and writing the diff to stdout, respectively). If a file has diagnostics, we
-            // need to avoid reading from and writing to the cache in these modes.
-            if match fix_mode {
-                flags::FixMode::Generate => true,
-                flags::FixMode::Apply | flags::FixMode::Diff => {
-                    diagnostics.is_empty() && fixed.is_empty()
-                }
-            } {
-                cache.update_lint(
-                    relative_path.to_owned(),
-                    &key,
-                    LintCacheData::from_diagnostics(
-                        &diagnostics,
-                        transformed.as_ipy_notebook().map(Notebook::index).cloned(),
-                    ),
-                );
-            }
-        }
+        // `FixMode::Apply` and `FixMode::Diff` rely on side-effects (writing to disk,
+        // and writing the diff to stdout, respectively). If a file has diagnostics
+        // with fixes, we need to avoid reading from and writing to the cache in these
+        // modes.
+        let use_fixes = match fix_mode {
+            flags::FixMode::Generate => true,
+            flags::FixMode::Apply | flags::FixMode::Diff => fixed.is_empty(),
+        };
+
+        // We don't cache files with diagnostics.
+        let linted = diagnostics.is_empty() && use_fixes;
+        cache.set_linted(relative_path.to_owned(), &key, linted);
    }

    let notebook_indexes = if let SourceKind::IpyNotebook(notebook) = transformed {
--- a/crates/ruff/src/main.rs
+++ b/crates/ruff/src/main.rs
@@ -19,7 +19,8 @@ static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
    any(
        target_arch = "x86_64",
        target_arch = "aarch64",
-        target_arch = "powerpc64"
+        target_arch = "powerpc64",
+        target_arch = "riscv64"
    )
 ))]
 #[global_allocator]
--- a/crates/ruff/src/printer.rs
+++ b/crates/ruff/src/printer.rs
@@ -15,8 +15,7 @@ use ruff_db::diagnostic::{
 use ruff_linter::fs::relativize_path;
 use ruff_linter::logging::LogLevel;
 use ruff_linter::message::{
-    Emitter, EmitterContext, GithubEmitter, GitlabEmitter, GroupedEmitter, SarifEmitter,
-    TextEmitter,
+    Emitter, EmitterContext, GithubEmitter, GroupedEmitter, SarifEmitter, TextEmitter,
 };
 use ruff_linter::notify_user;
 use ruff_linter::settings::flags::{self};
@@ -296,7 +295,11 @@ impl Printer {
                GithubEmitter.emit(writer, &diagnostics.inner, &context)?;
            }
            OutputFormat::Gitlab => {
-                GitlabEmitter::default().emit(writer, &diagnostics.inner, &context)?;
+                let config = DisplayDiagnosticConfig::default()
+                    .format(DiagnosticFormat::Gitlab)
+                    .preview(preview);
+                let value = DisplayDiagnostics::new(&context, &config, &diagnostics.inner);
+                write!(writer, "{value}")?;
            }
            OutputFormat::Pylint => {
                let config = DisplayDiagnosticConfig::default()
--- a/crates/ruff/tests/integration_test.rs
+++ b/crates/ruff/tests/integration_test.rs
@@ -115,12 +115,13 @@ fn stdin_error() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:8: F401 [*] `os` imported but unused
+    F401 [*] `os` imported but unused
+     --> -:1:8
      |
    1 | import os
-      |        ^^ F401
+      |        ^^
      |
-      = help: Remove unused import: `os`
+    help: Remove unused import: `os`

    Found 1 error.
    [*] 1 fixable with the `--fix` option.
@@ -139,12 +140,13 @@ fn stdin_filename() {
    success: false
    exit_code: 1
    ----- stdout -----
-    F401.py:1:8: F401 [*] `os` imported but unused
+    F401 [*] `os` imported but unused
+     --> F401.py:1:8
      |
    1 | import os
-      |        ^^ F401
+      |        ^^
      |
-      = help: Remove unused import: `os`
+    help: Remove unused import: `os`

    Found 1 error.
    [*] 1 fixable with the `--fix` option.
@@ -174,19 +176,21 @@ import bar   # unused import
    success: false
    exit_code: 1
    ----- stdout -----
-    bar.py:2:8: F401 [*] `bar` imported but unused
+    F401 [*] `bar` imported but unused
+     --> bar.py:2:8
      |
    2 | import bar   # unused import
-      |        ^^^ F401
+      |        ^^^
      |
-      = help: Remove unused import: `bar`
+    help: Remove unused import: `bar`

-    foo.py:2:8: F401 [*] `foo` imported but unused
+    F401 [*] `foo` imported but unused
+     --> foo.py:2:8
      |
    2 | import foo   # unused import
-      |        ^^^ F401
+      |        ^^^
      |
-      = help: Remove unused import: `foo`
+    help: Remove unused import: `foo`

    Found 2 errors.
    [*] 2 fixable with the `--fix` option.
@@ -208,12 +212,13 @@ fn check_warn_stdin_filename_with_files() {
    success: false
    exit_code: 1
    ----- stdout -----
-    F401.py:1:8: F401 [*] `os` imported but unused
+    F401 [*] `os` imported but unused
+     --> F401.py:1:8
      |
    1 | import os
-      |        ^^ F401
+      |        ^^
      |
-      = help: Remove unused import: `os`
+    help: Remove unused import: `os`

    Found 1 error.
    [*] 1 fixable with the `--fix` option.
@@ -234,12 +239,13 @@ fn stdin_source_type_py() {
    success: false
    exit_code: 1
    ----- stdout -----
-    TCH.py:1:8: F401 [*] `os` imported but unused
+    F401 [*] `os` imported but unused
+     --> TCH.py:1:8
      |
    1 | import os
-      |        ^^ F401
+      |        ^^
      |
-      = help: Remove unused import: `os`
+    help: Remove unused import: `os`

    Found 1 error.
    [*] 1 fixable with the `--fix` option.
@@ -471,10 +477,11 @@ fn stdin_fix_jupyter() {
     "nbformat_minor": 5
    }
    ----- stderr -----
-    Jupyter.ipynb:cell 3:1:7: F821 Undefined name `x`
+    F821 Undefined name `x`
+     --> Jupyter.ipynb:cell 3:1:7
      |
    1 | print(x)
-      |       ^ F821
+      |       ^
      |

    Found 3 errors (2 fixed, 1 remaining).
@@ -569,19 +576,21 @@ fn stdin_override_parser_ipynb() {
    success: false
    exit_code: 1
    ----- stdout -----
-    Jupyter.py:cell 1:1:8: F401 [*] `os` imported but unused
+    F401 [*] `os` imported but unused
+     --> Jupyter.py:cell 1:1:8
      |
    1 | import os
-      |        ^^ F401
+      |        ^^
      |
-      = help: Remove unused import: `os`
+    help: Remove unused import: `os`

-    Jupyter.py:cell 3:1:8: F401 [*] `sys` imported but unused
+    F401 [*] `sys` imported but unused
+     --> Jupyter.py:cell 3:1:8
      |
    1 | import sys
-      |        ^^^ F401
+      |        ^^^
      |
-      = help: Remove unused import: `sys`
+    help: Remove unused import: `sys`

    Found 2 errors.
    [*] 2 fixable with the `--fix` option.
@@ -605,12 +614,13 @@ fn stdin_override_parser_py() {
    success: false
    exit_code: 1
    ----- stdout -----
-    F401.ipynb:1:8: F401 [*] `os` imported but unused
+    F401 [*] `os` imported but unused
+     --> F401.ipynb:1:8
      |
    1 | import os
-      |        ^^ F401
+      |        ^^
      |
-      = help: Remove unused import: `os`
+    help: Remove unused import: `os`

    Found 1 error.
    [*] 1 fixable with the `--fix` option.
@@ -633,12 +643,13 @@ fn stdin_fix_when_not_fixable_should_still_print_contents() {
         print(sys.version)

    ----- stderr -----
-    -:3:4: F634 If test is a tuple, which is always `True`
+    F634 If test is a tuple, which is always `True`
+     --> -:3:4
      |
    1 | import sys
    2 |
    3 | if (1, 2):
-      |    ^^^^^^ F634
+      |    ^^^^^^
    4 |      print(sys.version)
      |

@@ -798,7 +809,8 @@ fn stdin_parse_error() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:16: invalid-syntax: Expected one or more symbol names after import
+    invalid-syntax: Expected one or more symbol names after import
+     --> -:1:16
      |
    1 | from foo import
      |                ^
@@ -818,14 +830,16 @@ fn stdin_multiple_parse_error() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:16: invalid-syntax: Expected one or more symbol names after import
+    invalid-syntax: Expected one or more symbol names after import
+     --> -:1:16
      |
    1 | from foo import
      |                ^
    2 | bar =
      |

-    -:2:6: invalid-syntax: Expected an expression
+    invalid-syntax: Expected an expression
+     --> -:2:6
      |
    1 | from foo import
    2 | bar =
@@ -847,7 +861,8 @@ fn parse_error_not_included() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:6: invalid-syntax: Expected an expression
+    invalid-syntax: Expected an expression
+     --> -:1:6
      |
    1 | foo =
      |      ^
@@ -867,10 +882,11 @@ fn full_output_preview() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: E741 Ambiguous variable name: `l`
+    E741 Ambiguous variable name: `l`
+     --> -:1:1
      |
    1 | l = 1
-      | ^ E741
+      | ^
      |

    Found 1 error.
@@ -895,10 +911,11 @@ preview = true
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: E741 Ambiguous variable name: `l`
+    E741 Ambiguous variable name: `l`
+     --> -:1:1
      |
    1 | l = 1
-      | ^ E741
+      | ^
      |

    Found 1 error.
@@ -916,10 +933,11 @@ fn full_output_format() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: E741 Ambiguous variable name: `l`
+    E741 Ambiguous variable name: `l`
+     --> -:1:1
      |
    1 | l = 1
-      | ^ E741
+      | ^
      |

    Found 1 error.
@@ -1406,7 +1424,9 @@ fn redirect_direct() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF950 Hey this is a test rule that was redirected from another.
+    RUF950 Hey this is a test rule that was redirected from another.
+    --> -:1:1
+
    Found 1 error.

    ----- stderr -----
@@ -1438,7 +1458,9 @@ fn redirect_prefix() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF950 Hey this is a test rule that was redirected from another.
+    RUF950 Hey this is a test rule that was redirected from another.
+    --> -:1:1
+
    Found 1 error.

    ----- stderr -----
@@ -1455,7 +1477,9 @@ fn deprecated_direct() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF920 Hey this is a deprecated test rule.
+    RUF920 Hey this is a deprecated test rule.
+    --> -:1:1
+
    Found 1 error.

    ----- stderr -----
@@ -1472,8 +1496,12 @@ fn deprecated_multiple_direct() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF920 Hey this is a deprecated test rule.
-    -:1:1: RUF921 Hey this is another deprecated test rule.
+    RUF920 Hey this is a deprecated test rule.
+    --> -:1:1
+
+    RUF921 Hey this is another deprecated test rule.
+    --> -:1:1
+
    Found 2 errors.

    ----- stderr -----
@@ -1491,8 +1519,12 @@ fn deprecated_indirect() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF920 Hey this is a deprecated test rule.
-    -:1:1: RUF921 Hey this is another deprecated test rule.
+    RUF920 Hey this is a deprecated test rule.
+    --> -:1:1
+
+    RUF921 Hey this is another deprecated test rule.
+    --> -:1:1
+
    Found 2 errors.

    ----- stderr -----
@@ -1638,22 +1670,23 @@ fn check_input_from_argfile() -> Result<()> {
        (file_a_path.display().to_string().as_str(), "/path/to/a.py"),
    ]}, {
        assert_cmd_snapshot!(cmd
-            .pass_stdin(""), @r###"
+            .pass_stdin(""), @r"
        success: false
        exit_code: 1
        ----- stdout -----
-        /path/to/a.py:1:8: F401 [*] `os` imported but unused
+        F401 [*] `os` imported but unused
+         --> /path/to/a.py:1:8
          |
        1 | import os
-          |        ^^ F401
+          |        ^^
          |
-          = help: Remove unused import: `os`
+        help: Remove unused import: `os`

        Found 1 error.
        [*] 1 fixable with the `--fix` option.

        ----- stderr -----
-        "###);
+        ");
    });

    Ok(())
@@ -1669,8 +1702,12 @@ fn check_hints_hidden_unsafe_fixes() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF901 [*] Hey this is a stable test rule with a safe fix.
-    -:1:1: RUF902 Hey this is a stable test rule with an unsafe fix.
+    RUF901 [*] Hey this is a stable test rule with a safe fix.
+    --> -:1:1
+
+    RUF902 Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
    Found 2 errors.
    [*] 1 fixable with the `--fix` option (1 hidden fix can be enabled with the `--unsafe-fixes` option).

@@ -1687,7 +1724,9 @@ fn check_hints_hidden_unsafe_fixes_with_no_safe_fixes() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF902 Hey this is a stable test rule with an unsafe fix.
+    RUF902 Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
    Found 1 error.
    No fixes available (1 hidden fix can be enabled with the `--unsafe-fixes` option).

@@ -1705,8 +1744,12 @@ fn check_no_hint_for_hidden_unsafe_fixes_when_disabled() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF901 [*] Hey this is a stable test rule with a safe fix.
-    -:1:1: RUF902 Hey this is a stable test rule with an unsafe fix.
+    RUF901 [*] Hey this is a stable test rule with a safe fix.
+    --> -:1:1
+
+    RUF902 Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
    Found 2 errors.
    [*] 1 fixable with the --fix option.

@@ -1725,7 +1768,9 @@ fn check_no_hint_for_hidden_unsafe_fixes_with_no_safe_fixes_when_disabled() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF902 Hey this is a stable test rule with an unsafe fix.
+    RUF902 Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
    Found 1 error.

    ----- stderr -----
@@ -1742,8 +1787,12 @@ fn check_shows_unsafe_fixes_with_opt_in() {
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF901 [*] Hey this is a stable test rule with a safe fix.
-    -:1:1: RUF902 [*] Hey this is a stable test rule with an unsafe fix.
+    RUF901 [*] Hey this is a stable test rule with a safe fix.
+    --> -:1:1
+
+    RUF902 [*] Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
    Found 2 errors.
    [*] 2 fixable with the --fix option.

@@ -1764,7 +1813,9 @@ fn fix_applies_safe_fixes_by_default() {
    # fix from stable-test-rule-safe-fix

    ----- stderr -----
-    -:1:1: RUF902 Hey this is a stable test rule with an unsafe fix.
+    RUF902 Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
    Found 2 errors (1 fixed, 1 remaining).
    No fixes available (1 hidden fix can be enabled with the `--unsafe-fixes` option).
    ");
@@ -1801,7 +1852,9 @@ fn fix_does_not_apply_display_only_fixes() {
    ----- stdout -----
    def add_to_list(item, some_list=[]): ...
    ----- stderr -----
-    -:1:1: RUF903 Hey this is a stable test rule with a display only fix.
+    RUF903 Hey this is a stable test rule with a display only fix.
+    --> -:1:1
+
    Found 1 error.
    ");
 }
@@ -1819,7 +1872,9 @@ fn fix_does_not_apply_display_only_fixes_with_unsafe_fixes_enabled() {
    ----- stdout -----
    def add_to_list(item, some_list=[]): ...
    ----- stderr -----
-    -:1:1: RUF903 Hey this is a stable test rule with a display only fix.
+    RUF903 Hey this is a stable test rule with a display only fix.
+    --> -:1:1
+
    Found 1 error.
    ");
 }
@@ -1836,7 +1891,9 @@ fn fix_only_unsafe_fixes_available() {
    ----- stdout -----

    ----- stderr -----
-    -:1:1: RUF902 Hey this is a stable test rule with an unsafe fix.
+    RUF902 Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
    Found 1 error.
    No fixes available (1 hidden fix can be enabled with the `--unsafe-fixes` option).
    ");
@@ -1972,8 +2029,12 @@ extend-unsafe-fixes = ["RUF901"]
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF901 Hey this is a stable test rule with a safe fix.
-    -:1:1: RUF902 Hey this is a stable test rule with an unsafe fix.
+    RUF901 Hey this is a stable test rule with a safe fix.
+    --> -:1:1
+
+    RUF902 Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
    Found 2 errors.
    No fixes available (2 hidden fixes can be enabled with the `--unsafe-fixes` option).

@@ -2004,8 +2065,12 @@ extend-safe-fixes = ["RUF902"]
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF901 [*] Hey this is a stable test rule with a safe fix.
-    -:1:1: RUF902 [*] Hey this is a stable test rule with an unsafe fix.
+    RUF901 [*] Hey this is a stable test rule with a safe fix.
+    --> -:1:1
+
+    RUF902 [*] Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
    Found 2 errors.
    [*] 2 fixable with the `--fix` option.

@@ -2038,8 +2103,12 @@ extend-safe-fixes = ["RUF902"]
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF901 [*] Hey this is a stable test rule with a safe fix.
-    -:1:1: RUF902 Hey this is a stable test rule with an unsafe fix.
+    RUF901 [*] Hey this is a stable test rule with a safe fix.
+    --> -:1:1
+
+    RUF902 Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
    Found 2 errors.
    [*] 1 fixable with the `--fix` option (1 hidden fix can be enabled with the `--unsafe-fixes` option).

@@ -2074,13 +2143,27 @@ extend-safe-fixes = ["RUF9"]
    success: false
    exit_code: 1
    ----- stdout -----
-    -:1:1: RUF900 Hey this is a stable test rule.
-    -:1:1: RUF901 Hey this is a stable test rule with a safe fix.
-    -:1:1: RUF902 [*] Hey this is a stable test rule with an unsafe fix.
-    -:1:1: RUF903 Hey this is a stable test rule with a display only fix.
-    -:1:1: RUF920 Hey this is a deprecated test rule.
-    -:1:1: RUF921 Hey this is another deprecated test rule.
-    -:1:1: RUF950 Hey this is a test rule that was redirected from another.
+    RUF900 Hey this is a stable test rule.
+    --> -:1:1
+
+    RUF901 Hey this is a stable test rule with a safe fix.
+    --> -:1:1
+
+    RUF902 [*] Hey this is a stable test rule with an unsafe fix.
+    --> -:1:1
+
+    RUF903 Hey this is a stable test rule with a display only fix.
+    --> -:1:1
+
+    RUF920 Hey this is a deprecated test rule.
+    --> -:1:1
+
+    RUF921 Hey this is another deprecated test rule.
+    --> -:1:1
+
+    RUF950 Hey this is a test rule that was redirected from another.
+    --> -:1:1
+
    Found 7 errors.
    [*] 1 fixable with the `--fix` option (1 hidden fix can be enabled with the `--unsafe-fixes` option).

@@ -2141,10 +2224,11 @@ def log(x, base) -> float:
    success: false
    exit_code: 1
    ----- stdout -----
-    -:2:5: D417 Missing argument description in the docstring for `log`: `base`
+    D417 Missing argument description in the docstring for `log`: `base`
+     --> -:2:5
      |
    2 | def log(x, base) -> float:
-      |     ^^^ D417
+      |     ^^^
    3 |     """Calculate natural log of a value
      |

@@ -2177,14 +2261,15 @@ select = ["RUF017"]
    success: false
    exit_code: 1
    ----- stdout -----
-    -:3:1: RUF017 Avoid quadratic list summation
+    RUF017 Avoid quadratic list summation
+     --> -:3:1
      |
    1 | x = [1, 2, 3]
    2 | y = [4, 5, 6]
    3 | sum([x, y], [])
-      | ^^^^^^^^^^^^^^^ RUF017
+      | ^^^^^^^^^^^^^^^
      |
-      = help: Replace with `functools.reduce`
+    help: Replace with `functools.reduce`

    Found 1 error.
    No fixes available (1 hidden fix can be enabled with the `--unsafe-fixes` option).
@@ -2217,14 +2302,15 @@ unfixable = ["RUF"]
    success: false
    exit_code: 1
    ----- stdout -----
-    -:3:1: RUF017 Avoid quadratic list summation
+    RUF017 Avoid quadratic list summation
+     --> -:3:1
      |
    1 | x = [1, 2, 3]
    2 | y = [4, 5, 6]
    3 | sum([x, y], [])
-      | ^^^^^^^^^^^^^^^ RUF017
+      | ^^^^^^^^^^^^^^^
      |
-      = help: Replace with `functools.reduce`
+    help: Replace with `functools.reduce`

    Found 1 error.

@@ -2246,10 +2332,11 @@ fn pyproject_toml_stdin_syntax_error() {
    success: false
    exit_code: 1
    ----- stdout -----
-    pyproject.toml:1:9: RUF200 Failed to parse pyproject.toml: unclosed table, expected `]`
+    RUF200 Failed to parse pyproject.toml: unclosed table, expected `]`
+     --> pyproject.toml:1:9
      |
    1 | [project
-      |         ^ RUF200
+      |         ^
      |

    Found 1 error.
@@ -2271,11 +2358,12 @@ fn pyproject_toml_stdin_schema_error() {
    success: false
    exit_code: 1
    ----- stdout -----
-    pyproject.toml:2:8: RUF200 Failed to parse pyproject.toml: invalid type: integer `1`, expected a string
+    RUF200 Failed to parse pyproject.toml: invalid type: integer `1`, expected a string
+     --> pyproject.toml:2:8
      |
    1 | [project]
    2 | name = 1
-      |        ^ RUF200
+      |        ^
      |

    Found 1 error.
@@ -2363,11 +2451,12 @@ fn pyproject_toml_stdin_schema_error_fix() {
    [project]
    name = 1
    ----- stderr -----
-    pyproject.toml:2:8: RUF200 Failed to parse pyproject.toml: invalid type: integer `1`, expected a string
+    RUF200 Failed to parse pyproject.toml: invalid type: integer `1`, expected a string
+     --> pyproject.toml:2:8
      |
    1 | [project]
    2 | name = 1
-      |        ^ RUF200
+      |        ^
      |

    Found 1 error.
--- a/crates/ruff/tests/lint.rs
+++ b/crates/ruff/tests/lint.rs
@@ -5588,15 +5588,15 @@ fn cookiecutter_globbing() -> Result<()> {
                .args(STDIN_BASE_OPTIONS)
                .arg("--select=F811")
                .current_dir(tempdir.path()), @r"
-			success: false
-			exit_code: 1
-			----- stdout -----
-			{{cookiecutter.repo_name}}/tests/maintest.py:3:8: F811 [*] Redefinition of unused `foo` from line 1
-			Found 1 error.
-			[*] 1 fixable with the `--fix` option.
+        success: false
+        exit_code: 1
+        ----- stdout -----
+        {{cookiecutter.repo_name}}/tests/maintest.py:3:8: F811 [*] Redefinition of unused `foo` from line 1: `foo` redefined here
+        Found 1 error.
+        [*] 1 fixable with the `--fix` option.

-			----- stderr -----
-		");
+        ----- stderr -----
+        ");
    });

    Ok(())
@@ -5801,3 +5801,32 @@ fn future_annotations_preview_warning() {
    ",
    );
 }
+
+#[test]
+fn up045_nested_optional_flatten_all() {
+    let contents = "\
+from typing import Optional
+nested_optional: Optional[Optional[Optional[str]]] = None
+";
+
+    assert_cmd_snapshot!(
+        Command::new(get_cargo_bin(BIN_NAME))
+            .args(STDIN_BASE_OPTIONS)
+            .args(["--select", "UP045", "--diff", "--target-version", "py312"])
+            .arg("-")
+            .pass_stdin(contents),
+        @r"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+    @@ -1,2 +1,2 @@
+     from typing import Optional
+    -nested_optional: Optional[Optional[Optional[str]]] = None
+    +nested_optional: str | None = None
+
+
+    ----- stderr -----
+    Would fix 1 error.
+    ",
+    );
+}
--- a/crates/ruff/tests/snapshots/lint__output_format_full.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_full.snap
@@ -16,25 +16,28 @@ info:
 success: false
 exit_code: 1
 ----- stdout -----
-input.py:1:8: F401 [*] `os` imported but unused
+F401 [*] `os` imported but unused
+ --> input.py:1:8
  |
 1 | import os  # F401
-  |        ^^ F401
+  |        ^^
 2 | x = y      # F821
 3 | match 42:  # invalid-syntax
  |
-  = help: Remove unused import: `os`
+help: Remove unused import: `os`

-input.py:2:5: F821 Undefined name `y`
+F821 Undefined name `y`
+ --> input.py:2:5
  |
 1 | import os  # F401
 2 | x = y      # F821
-  |     ^ F821
+  |     ^
 3 | match 42:  # invalid-syntax
 4 |     case _: ...
  |

-input.py:3:1: invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+ --> input.py:3:1
  |
 1 | import os  # F401
 2 | x = y      # F821
--- a/crates/ruff/tests/snapshots/lint__output_format_gitlab.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_gitlab.snap
@@ -19,60 +19,60 @@ exit_code: 1
 [
  {
    "check_name": "F401",
-    "description": "`os` imported but unused",
+    "description": "F401: `os` imported but unused",
+    "severity": "major",
    "fingerprint": "4dbad37161e65c72",
    "location": {
      "path": "input.py",
      "positions": {
        "begin": {
-          "column": 8,
-          "line": 1
+          "line": 1,
+          "column": 8
        },
        "end": {
-          "column": 10,
-          "line": 1
+          "line": 1,
+          "column": 10
        }
      }
-    },
-    "severity": "major"
+    }
  },
  {
    "check_name": "F821",
-    "description": "Undefined name `y`",
+    "description": "F821: Undefined name `y`",
+    "severity": "major",
    "fingerprint": "7af59862a085230",
    "location": {
      "path": "input.py",
      "positions": {
        "begin": {
-          "column": 5,
-          "line": 2
+          "line": 2,
+          "column": 5
        },
        "end": {
-          "column": 6,
-          "line": 2
+          "line": 2,
+          "column": 6
        }
      }
-    },
-    "severity": "major"
+    }
  },
  {
-    "check_name": "syntax-error",
-    "description": "Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)",
+    "check_name": "invalid-syntax",
+    "description": "invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)",
+    "severity": "major",
    "fingerprint": "e558cec859bb66e8",
    "location": {
      "path": "input.py",
      "positions": {
        "begin": {
-          "column": 1,
-          "line": 3
+          "line": 3,
+          "column": 1
        },
        "end": {
-          "column": 6,
-          "line": 3
+          "line": 3,
+          "column": 6
        }
      }
-    },
-    "severity": "major"
+    }
  }
 ]
 ----- stderr -----
--- a/crates/ruff_annotate_snippets/src/renderer/display_list.rs
+++ b/crates/ruff_annotate_snippets/src/renderer/display_list.rs
@@ -1201,11 +1201,16 @@ fn format_snippet<'m>(

    let is_file_level = snippet.annotations.iter().any(|ann| ann.is_file_level);
    if is_file_level {
-        assert!(
-            snippet.source.is_empty(),
-            "Non-empty file-level snippet that won't be rendered: {:?}",
-            snippet.source
-        );
+        // TODO(brent) enable this assertion again once we set `is_file_level` for individual rules.
+        // It's causing too many false positives currently when the default is to make any
+        // annotation with a default range file-level. See
+        // https://github.com/astral-sh/ruff/issues/19688.
+        //
+        // assert!(
+        //     snippet.source.is_empty(),
+        //     "Non-empty file-level snippet that won't be rendered: {:?}",
+        //     snippet.source
+        // );
        let header = format_header(origin, main_range, &[], is_first, snippet.cell_index);
        return DisplaySet {
            display_lines: header.map_or_else(Vec::new, |header| vec![header]),
@@ -1273,13 +1278,20 @@ fn format_header<'a>(
                ..
            } = item
            {
-                if main_range >= range.0 && main_range < range.1 + max(*end_line as usize, 1) {
+                // At the very end of the `main_range`, report the location as the first character
+                // in the next line instead of falling back to the default location of `1:1`. This
+                // is another divergence from upstream.
+                let end_of_range = range.1 + max(*end_line as usize, 1);
+                if main_range >= range.0 && main_range < end_of_range {
                    let char_column = text[0..(main_range - range.0).min(text.len())]
                        .chars()
                        .count();
                    col = char_column + 1;
                    line_offset = lineno.unwrap_or(1);
                    break;
+                } else if main_range == end_of_range {
+                    line_offset = lineno.map_or(1, |line| line + 1);
+                    break;
                }
            }
        }
--- a/crates/ruff_benchmark/Cargo.toml
+++ b/crates/ruff_benchmark/Cargo.toml
@@ -86,5 +86,5 @@ walltime = ["ruff_db/os", "ty_project", "divan"]
 [target.'cfg(target_os = "windows")'.dev-dependencies]
 mimalloc = { workspace = true }

-[target.'cfg(all(not(target_os = "windows"), not(target_os = "openbsd"), any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "powerpc64")))'.dev-dependencies]
+[target.'cfg(all(not(target_os = "windows"), not(target_os = "openbsd"), any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "powerpc64", target_arch = "riscv64")))'.dev-dependencies]
 tikv-jemallocator = { workspace = true }
--- a/crates/ruff_benchmark/benches/formatter.rs
+++ b/crates/ruff_benchmark/benches/formatter.rs
@@ -21,7 +21,8 @@ static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
    any(
        target_arch = "x86_64",
        target_arch = "aarch64",
-        target_arch = "powerpc64"
+        target_arch = "powerpc64",
+        target_arch = "riscv64"
    )
 ))]
 #[global_allocator]
--- a/crates/ruff_benchmark/benches/lexer.rs
+++ b/crates/ruff_benchmark/benches/lexer.rs
@@ -18,7 +18,8 @@ static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
    any(
        target_arch = "x86_64",
        target_arch = "aarch64",
-        target_arch = "powerpc64"
+        target_arch = "powerpc64",
+        target_arch = "riscv64"
    )
 ))]
 #[global_allocator]
--- a/crates/ruff_benchmark/benches/linter.rs
+++ b/crates/ruff_benchmark/benches/linter.rs
@@ -26,7 +26,8 @@ static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
    any(
        target_arch = "x86_64",
        target_arch = "aarch64",
-        target_arch = "powerpc64"
+        target_arch = "powerpc64",
+        target_arch = "riscv64"
    )
 ))]
 #[global_allocator]
@@ -42,7 +43,8 @@ static GLOBAL: tikv_jemallocator::Jemalloc = tikv_jemallocator::Jemalloc;
    any(
        target_arch = "x86_64",
        target_arch = "aarch64",
-        target_arch = "powerpc64"
+        target_arch = "powerpc64",
+        target_arch = "riscv64"
    )
 ))]
 #[unsafe(export_name = "_rjem_malloc_conf")]
@@ -77,8 +79,11 @@ fn benchmark_linter(mut group: BenchmarkGroup, settings: &LinterSettings) {
                b.iter_batched(
                    || parsed.clone(),
                    |parsed| {
+                        // Assert that file contains no parse errors
+                        assert!(parsed.has_valid_syntax());
+
                        let path = case.path();
-                        let result = lint_only(
+                        lint_only(
                            &path,
                            None,
                            settings,
@@ -86,10 +91,7 @@ fn benchmark_linter(mut group: BenchmarkGroup, settings: &LinterSettings) {
                            &SourceKind::Python(case.code().to_string()),
                            PySourceType::from(path.as_path()),
                            ParseSource::Precomputed(parsed),
-                        );
-
-                        // Assert that file contains no parse errors
-                        assert!(!result.has_syntax_errors());
+                        )
                    },
                    criterion::BatchSize::SmallInput,
                );
--- a/crates/ruff_benchmark/benches/parser.rs
+++ b/crates/ruff_benchmark/benches/parser.rs
@@ -20,7 +20,8 @@ static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
    any(
        target_arch = "x86_64",
        target_arch = "aarch64",
-        target_arch = "powerpc64"
+        target_arch = "powerpc64",
+        target_arch = "riscv64"
    )
 ))]
 #[global_allocator]
--- a/crates/ruff_benchmark/benches/ty.rs
+++ b/crates/ruff_benchmark/benches/ty.rs
@@ -450,9 +450,6 @@ fn benchmark_complex_constrained_attributes_2(criterion: &mut Criterion) {
                    r#"
                    class C:
                        def f(self: "C"):
-                            self.a = ""
-                            self.b = ""
-
                            if isinstance(self.a, str):
                                return

@@ -466,6 +463,56 @@ fn benchmark_complex_constrained_attributes_2(criterion: &mut Criterion) {
                                return
                            if isinstance(self.b, str):
                                return
+                            if isinstance(self.b, str):
+                                return
+                            if isinstance(self.b, str):
+                                return
+
+                            self.a = ""
+                            self.b = ""
+                    "#,
+                )
+            },
+            |case| {
+                let Case { db, .. } = case;
+                let result = db.check();
+                assert_eq!(result.len(), 0);
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn benchmark_complex_constrained_attributes_3(criterion: &mut Criterion) {
+    setup_rayon();
+
+    criterion.bench_function("ty_micro[complex_constrained_attributes_3]", |b| {
+        b.iter_batched_ref(
+            || {
+                // This is a regression test for https://github.com/astral-sh/ty/issues/758
+                setup_micro_case(
+                    r#"
+                    class GridOut:
+                        def __init__(self: "GridOut") -> None:
+                            self._buffer = b""
+
+                        def _read_size_or_line(self: "GridOut", size: int = -1):
+                            if size > self._position:
+                                size = self._position
+                                pass
+                            if size == 0:
+                                return bytes()
+
+                            while size > 0:
+                                if self._buffer:
+                                    buf = self._buffer
+                                    self._buffer = b""
+                                else:
+                                    buf = b""
+
+                                if len(buf) > size:
+                                    self._buffer = buf
+                                    self._position -= len(self._buffer)
                    "#,
                )
            },
@@ -668,6 +715,7 @@ criterion_group!(
    benchmark_tuple_implicit_instance_attributes,
    benchmark_complex_constrained_attributes_1,
    benchmark_complex_constrained_attributes_2,
+    benchmark_complex_constrained_attributes_3,
    benchmark_many_enum_members,
 );
 criterion_group!(project, anyio, attrs, hydra, datetype);
--- a/crates/ruff_benchmark/benches/ty_walltime.rs
+++ b/crates/ruff_benchmark/benches/ty_walltime.rs
@@ -218,6 +218,24 @@ static TANJUN: std::sync::LazyLock<Benchmark<'static>> = std::sync::LazyLock::ne
    )
 });

+static STATIC_FRAME: std::sync::LazyLock<Benchmark<'static>> = std::sync::LazyLock::new(|| {
+    Benchmark::new(
+        RealWorldProject {
+            name: "static-frame",
+            repository: "https://github.com/static-frame/static-frame",
+            commit: "34962b41baca5e7f98f5a758d530bff02748a421",
+            paths: vec![SystemPath::new("static_frame")],
+            // N.B. `arraykit` is installed as a dependency during mypy_primer runs,
+            // but it takes much longer to be installed in a Codspeed run than it does in a mypy_primer run
+            // (seems to be built from source on the Codspeed CI runners for some reason).
+            dependencies: vec!["numpy"],
+            max_dep_date: "2025-08-09",
+            python_version: PythonVersion::PY311,
+        },
+        500,
+    )
+});
+
 #[track_caller]
 fn run_single_threaded(bencher: Bencher, benchmark: &Benchmark) {
    bencher
@@ -232,7 +250,7 @@ fn small(bencher: Bencher, benchmark: &Benchmark) {
    run_single_threaded(bencher, benchmark);
 }

-#[bench(args=[&*COLOUR_SCIENCE, &*PANDAS], sample_size=1, sample_count=3)]
+#[bench(args=[&*COLOUR_SCIENCE, &*PANDAS, &*STATIC_FRAME], sample_size=1, sample_count=3)]
 fn medium(bencher: Bencher, benchmark: &Benchmark) {
    run_single_threaded(bencher, benchmark);
 }
--- a/crates/ruff_db/Cargo.toml
+++ b/crates/ruff_db/Cargo.toml
@@ -34,12 +34,14 @@ glob = { workspace = true }
 ignore = { workspace = true, optional = true }
 matchit = { workspace = true }
 path-slash = { workspace = true }
+pathdiff = { workspace = true }
 quick-junit = { workspace = true, optional = true }
 rustc-hash = { workspace = true }
 salsa = { workspace = true }
 schemars = { workspace = true, optional = true }
 serde = { workspace = true, optional = true }
 serde_json = { workspace = true, optional = true }
+similar = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 tracing-subscriber = { workspace = true, optional = true }
@@ -52,7 +54,7 @@ web-time = { version = "1.1.0" }
 etcetera = { workspace = true, optional = true }

 [dev-dependencies]
-insta = { workspace = true }
+insta = { workspace = true, features = ["filters"] }
 tempfile = { workspace = true }

 [features]
--- a/crates/ruff_db/src/diagnostic/mod.rs
+++ b/crates/ruff_db/src/diagnostic/mod.rs
@@ -254,6 +254,11 @@ impl Diagnostic {
            .find(|ann| ann.is_primary)
    }

+    /// Returns a mutable borrow of all annotations of this diagnostic.
+    pub fn annotations_mut(&mut self) -> impl Iterator<Item = &mut Annotation> {
+        Arc::make_mut(&mut self.inner).annotations.iter_mut()
+    }
+
    /// Returns the "primary" span of this diagnostic if one exists.
    ///
    /// When there are multiple primary spans, then the first one that was
@@ -310,11 +315,21 @@ impl Diagnostic {
        &self.inner.subs
    }

+    /// Returns a mutable borrow of the sub-diagnostics of this diagnostic.
+    pub fn sub_diagnostics_mut(&mut self) -> impl Iterator<Item = &mut SubDiagnostic> {
+        Arc::make_mut(&mut self.inner).subs.iter_mut()
+    }
+
    /// Returns the fix for this diagnostic if it exists.
    pub fn fix(&self) -> Option<&Fix> {
        self.inner.fix.as_ref()
    }

+    #[cfg(test)]
+    pub(crate) fn fix_mut(&mut self) -> Option<&mut Fix> {
+        Arc::make_mut(&mut self.inner).fix.as_mut()
+    }
+
    /// Set the fix for this diagnostic.
    pub fn set_fix(&mut self, fix: Fix) {
        debug_assert!(
@@ -621,6 +636,11 @@ impl SubDiagnostic {
        &self.inner.annotations
    }

+    /// Returns a mutable borrow of the annotations of this sub-diagnostic.
+    pub fn annotations_mut(&mut self) -> impl Iterator<Item = &mut Annotation> {
+        self.inner.annotations.iter_mut()
+    }
+
    /// Returns a shared borrow of the "primary" annotation of this diagnostic
    /// if one exists.
    ///
@@ -1279,6 +1299,10 @@ pub struct DisplayDiagnosticConfig {
    hide_severity: bool,
    /// Whether to show the availability of a fix in a diagnostic.
    show_fix_status: bool,
+    /// Whether to show the diff for an available fix after the main diagnostic.
+    ///
+    /// This currently only applies to `DiagnosticFormat::Full`.
+    show_fix_diff: bool,
    /// The lowest applicability that should be shown when reporting diagnostics.
    fix_applicability: Applicability,
 }
@@ -1326,6 +1350,14 @@ impl DisplayDiagnosticConfig {
        }
    }

+    /// Whether to show a diff for an available fix after the main diagnostic.
+    pub fn show_fix_diff(self, yes: bool) -> DisplayDiagnosticConfig {
+        DisplayDiagnosticConfig {
+            show_fix_diff: yes,
+            ..self
+        }
+    }
+
    /// Set the lowest fix applicability that should be shown.
    ///
    /// In other words, an applicability of `Safe` (the default) would suppress showing fixes or fix
@@ -1349,6 +1381,7 @@ impl Default for DisplayDiagnosticConfig {
            preview: false,
            hide_severity: false,
            show_fix_status: false,
+            show_fix_diff: false,
            fix_applicability: Applicability::Safe,
        }
    }
@@ -1402,6 +1435,11 @@ pub enum DiagnosticFormat {
    /// Print diagnostics in the format expected by JUnit.
    #[cfg(feature = "junit")]
    Junit,
+    /// Print diagnostics in the JSON format used by GitLab [Code Quality] reports.
+    ///
+    /// [Code Quality]: https://docs.gitlab.com/ee/ci/testing/code_quality.html#implement-a-custom-tool
+    #[cfg(feature = "serde")]
+    Gitlab,
 }

 /// A representation of the kinds of messages inside a diagnostic.
--- a/crates/ruff_db/src/diagnostic/render.rs
+++ b/crates/ruff_db/src/diagnostic/render.rs
@@ -2,15 +2,15 @@ use std::borrow::Cow;
 use std::collections::BTreeMap;
 use std::path::Path;

+use full::FullRenderer;
 use ruff_annotate_snippets::{
    Annotation as AnnotateAnnotation, Level as AnnotateLevel, Message as AnnotateMessage,
-    Renderer as AnnotateRenderer, Snippet as AnnotateSnippet,
+    Snippet as AnnotateSnippet,
 };
 use ruff_notebook::{Notebook, NotebookIndex};
 use ruff_source_file::{LineIndex, OneIndexed, SourceCode};
 use ruff_text_size::{TextLen, TextRange, TextSize};

-use crate::diagnostic::stylesheet::DiagnosticStylesheet;
 use crate::{
    Db,
    files::File,
@@ -31,6 +31,8 @@ mod azure;
 mod concise;
 mod full;
 #[cfg(feature = "serde")]
+mod gitlab;
+#[cfg(feature = "serde")]
 mod json;
 #[cfg(feature = "serde")]
 mod json_lines;
@@ -111,37 +113,7 @@ impl std::fmt::Display for DisplayDiagnostics<'_> {
                ConciseRenderer::new(self.resolver, self.config).render(f, self.diagnostics)?;
            }
            DiagnosticFormat::Full => {
-                let stylesheet = if self.config.color {
-                    DiagnosticStylesheet::styled()
-                } else {
-                    DiagnosticStylesheet::plain()
-                };
-
-                let mut renderer = if self.config.color {
-                    AnnotateRenderer::styled()
-                } else {
-                    AnnotateRenderer::plain()
-                }
-                .cut_indicator("…");
-
-                renderer = renderer
-                    .error(stylesheet.error)
-                    .warning(stylesheet.warning)
-                    .info(stylesheet.info)
-                    .note(stylesheet.note)
-                    .help(stylesheet.help)
-                    .line_no(stylesheet.line_no)
-                    .emphasis(stylesheet.emphasis)
-                    .none(stylesheet.none);
-
-                for diag in self.diagnostics {
-                    let resolved = Resolved::new(self.resolver, diag, self.config);
-                    let renderable = resolved.to_renderable(self.config.context);
-                    for diag in renderable.diagnostics.iter() {
-                        writeln!(f, "{}", renderer.render(diag.to_annotate()))?;
-                    }
-                    writeln!(f)?;
-                }
+                FullRenderer::new(self.resolver, self.config).render(f, self.diagnostics)?;
            }
            DiagnosticFormat::Azure => {
                AzureRenderer::new(self.resolver).render(f, self.diagnostics)?;
@@ -166,6 +138,10 @@ impl std::fmt::Display for DisplayDiagnostics<'_> {
            DiagnosticFormat::Junit => {
                junit::JunitRenderer::new(self.resolver).render(f, self.diagnostics)?;
            }
+            #[cfg(feature = "serde")]
+            DiagnosticFormat::Gitlab => {
+                gitlab::GitlabRenderer::new(self.resolver).render(f, self.diagnostics)?;
+            }
        }

        Ok(())
@@ -242,7 +218,12 @@ impl<'a> ResolvedDiagnostic<'a> {
            .annotations
            .iter()
            .filter_map(|ann| {
-                let path = ann.span.file.path(resolver);
+                let path = ann
+                    .span
+                    .file
+                    .relative_path(resolver)
+                    .to_str()
+                    .unwrap_or_else(|| ann.span.file.path(resolver));
                let diagnostic_source = ann.span.file.diagnostic_source(resolver);
                ResolvedAnnotation::new(path, &diagnostic_source, ann, resolver)
            })
@@ -289,7 +270,12 @@ impl<'a> ResolvedDiagnostic<'a> {
            .annotations
            .iter()
            .filter_map(|ann| {
-                let path = ann.span.file.path(resolver);
+                let path = ann
+                    .span
+                    .file
+                    .relative_path(resolver)
+                    .to_str()
+                    .unwrap_or_else(|| ann.span.file.path(resolver));
                let diagnostic_source = ann.span.file.diagnostic_source(resolver);
                ResolvedAnnotation::new(path, &diagnostic_source, ann, resolver)
            })
@@ -655,6 +641,22 @@ impl<'r> RenderableSnippet<'r> {
            .as_source_code()
            .slice(TextRange::new(snippet_start, snippet_end));

+        // Strip the BOM from the beginning of the snippet, if present. Doing this here saves us the
+        // trouble of updating the annotation ranges in `replace_unprintable`, and also allows us to
+        // check that the BOM is at the very beginning of the file, not just the beginning of the
+        // snippet.
+        const BOM: char = '\u{feff}';
+        let bom_len = BOM.text_len();
+        let (snippet, snippet_start) =
+            if snippet_start == TextSize::ZERO && snippet.starts_with(BOM) {
+                (
+                    &snippet[bom_len.to_usize()..],
+                    snippet_start + TextSize::new(bom_len.to_u32()),
+                )
+            } else {
+                (snippet, snippet_start)
+            };
+
        let annotations = anns
            .iter()
            .map(|ann| RenderableAnnotation::new(snippet_start, ann))
@@ -719,7 +721,11 @@ impl<'r> RenderableAnnotation<'r> {
    /// lifetime parameter here refers to the lifetime of the resolver that
    /// created the given `ResolvedAnnotation`.
    fn new(snippet_start: TextSize, ann: &'_ ResolvedAnnotation<'r>) -> RenderableAnnotation<'r> {
-        let range = ann.range - snippet_start;
+        // This should only ever saturate if a BOM is present _and_ the annotation range points
+        // before the BOM (i.e. at offset 0). In Ruff this typically results from the use of
+        // `TextRange::default()` for a diagnostic range instead of a range relative to file
+        // contents.
+        let range = ann.range.checked_sub(snippet_start).unwrap_or(ann.range);
        RenderableAnnotation {
            range,
            message: ann.message,
@@ -1000,7 +1006,12 @@ fn replace_unprintable<'r>(
    let mut last_end = 0;
    let mut result = String::new();
    for (index, c) in source.char_indices() {
-        if let Some(printable) = unprintable_replacement(c) {
+        // normalize `\r` line endings but don't double `\r\n`
+        if c == '\r' && !source[index + 1..].starts_with("\n") {
+            result.push_str(&source[last_end..index]);
+            result.push('\n');
+            last_end = index + 1;
+        } else if let Some(printable) = unprintable_replacement(c) {
            result.push_str(&source[last_end..index]);

            let len = printable.text_len().to_u32();
@@ -2617,6 +2628,13 @@ watermelon
            self.config = config;
        }

+        /// Show a diff for the fix when rendering.
+        pub(super) fn show_fix_diff(&mut self, yes: bool) {
+            let mut config = std::mem::take(&mut self.config);
+            config = config.show_fix_diff(yes);
+            self.config = config;
+        }
+
        /// The lowest fix applicability to show when rendering.
        pub(super) fn fix_applicability(&mut self, applicability: Applicability) {
            let mut config = std::mem::take(&mut self.config);
--- a/crates/ruff_db/src/diagnostic/render/full.rs
+++ b/crates/ruff_db/src/diagnostic/render/full.rs
@@ -1,7 +1,304 @@
+use std::borrow::Cow;
+use std::num::NonZeroUsize;
+
+use anstyle::Style;
+use ruff_notebook::NotebookIndex;
+use similar::{ChangeTag, TextDiff};
+
+use ruff_annotate_snippets::Renderer as AnnotateRenderer;
+use ruff_diagnostics::{Applicability, Fix};
+use ruff_source_file::OneIndexed;
+use ruff_text_size::{Ranged, TextLen, TextRange, TextSize};
+
+use crate::diagnostic::render::{FileResolver, Resolved};
+use crate::diagnostic::stylesheet::{DiagnosticStylesheet, fmt_styled};
+use crate::diagnostic::{Diagnostic, DiagnosticSource, DisplayDiagnosticConfig};
+
+pub(super) struct FullRenderer<'a> {
+    resolver: &'a dyn FileResolver,
+    config: &'a DisplayDiagnosticConfig,
+}
+
+impl<'a> FullRenderer<'a> {
+    pub(super) fn new(resolver: &'a dyn FileResolver, config: &'a DisplayDiagnosticConfig) -> Self {
+        Self { resolver, config }
+    }
+
+    pub(super) fn render(
+        &self,
+        f: &mut std::fmt::Formatter,
+        diagnostics: &[Diagnostic],
+    ) -> std::fmt::Result {
+        let stylesheet = if self.config.color {
+            DiagnosticStylesheet::styled()
+        } else {
+            DiagnosticStylesheet::plain()
+        };
+
+        let mut renderer = if self.config.color {
+            AnnotateRenderer::styled()
+        } else {
+            AnnotateRenderer::plain()
+        }
+        .cut_indicator("…");
+
+        renderer = renderer
+            .error(stylesheet.error)
+            .warning(stylesheet.warning)
+            .info(stylesheet.info)
+            .note(stylesheet.note)
+            .help(stylesheet.help)
+            .line_no(stylesheet.line_no)
+            .emphasis(stylesheet.emphasis)
+            .none(stylesheet.none);
+
+        for diag in diagnostics {
+            let resolved = Resolved::new(self.resolver, diag, self.config);
+            let renderable = resolved.to_renderable(self.config.context);
+            for diag in renderable.diagnostics.iter() {
+                writeln!(f, "{}", renderer.render(diag.to_annotate()))?;
+            }
+            writeln!(f)?;
+
+            if self.config.show_fix_diff {
+                if let Some(diff) = Diff::from_diagnostic(diag, &stylesheet, self.resolver) {
+                    writeln!(f, "{diff}")?;
+                }
+            }
+        }
+
+        Ok(())
+    }
+}
+
+/// Renders a diff that shows the code fixes.
+///
+/// The implementation isn't fully fledged out and only used by tests. Before using in production, try
+/// * Improve layout
+/// * Replace tabs with spaces for a consistent experience across terminals
+/// * Replace zero-width whitespaces
+/// * Print a simpler diff if only a single line has changed
+/// * Compute the diff from the `Edit` because diff calculation is expensive.
+struct Diff<'a> {
+    fix: &'a Fix,
+    diagnostic_source: DiagnosticSource,
+    notebook_index: Option<NotebookIndex>,
+    stylesheet: &'a DiagnosticStylesheet,
+}
+
+impl<'a> Diff<'a> {
+    fn from_diagnostic(
+        diagnostic: &'a Diagnostic,
+        stylesheet: &'a DiagnosticStylesheet,
+        resolver: &'a dyn FileResolver,
+    ) -> Option<Diff<'a>> {
+        let file = &diagnostic.primary_span_ref()?.file;
+        Some(Diff {
+            fix: diagnostic.fix()?,
+            diagnostic_source: file.diagnostic_source(resolver),
+            notebook_index: resolver.notebook_index(file),
+            stylesheet,
+        })
+    }
+}
+
+impl std::fmt::Display for Diff<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let source_code = self.diagnostic_source.as_source_code();
+        let source_text = source_code.text();
+
+        // Partition the source code into end offsets for each cell. If `self.notebook_index` is
+        // `None`, indicating a regular script file, all the lines will be in one "cell" under the
+        // `None` key.
+        let cells = if let Some(notebook_index) = &self.notebook_index {
+            let mut last_cell = OneIndexed::MIN;
+            let mut cells: Vec<(Option<OneIndexed>, TextSize)> = Vec::new();
+            for (row, cell) in notebook_index.iter() {
+                if cell != last_cell {
+                    let offset = source_code.line_start(row);
+                    cells.push((Some(last_cell), offset));
+                    last_cell = cell;
+                }
+            }
+            cells.push((Some(last_cell), source_text.text_len()));
+            cells
+        } else {
+            vec![(None, source_text.text_len())]
+        };
+
+        let message = match self.fix.applicability() {
+            // TODO(zanieb): Adjust this messaging once it's user-facing
+            Applicability::Safe => "Safe fix",
+            Applicability::Unsafe => "Unsafe fix",
+            Applicability::DisplayOnly => "Display-only fix",
+        };
+
+        // TODO(brent) `stylesheet.separator` is cyan rather than blue, as we had before. I think
+        // we're getting rid of this soon anyway, so I didn't think it was worth adding another
+        // style to the stylesheet temporarily. The color doesn't appear at all in the snapshot
+        // tests, which is the only place these are currently used.
+        writeln!(f, "ℹ {}", fmt_styled(message, self.stylesheet.separator))?;
+
+        let mut last_end = TextSize::ZERO;
+        for (cell, offset) in cells {
+            let range = TextRange::new(last_end, offset);
+            last_end = offset;
+            let input = source_code.slice(range);
+
+            let mut output = String::with_capacity(input.len());
+            let mut last_end = range.start();
+
+            let mut applied = 0;
+            for edit in self.fix.edits() {
+                if range.contains_range(edit.range()) {
+                    output.push_str(source_code.slice(TextRange::new(last_end, edit.start())));
+                    output.push_str(edit.content().unwrap_or_default());
+                    last_end = edit.end();
+                    applied += 1;
+                }
+            }
+
+            // No edits were applied, so there's no need to diff.
+            if applied == 0 {
+                continue;
+            }
+
+            output.push_str(&source_text[usize::from(last_end)..usize::from(range.end())]);
+
+            let diff = TextDiff::from_lines(input, &output);
+
+            let (largest_old, largest_new) = diff
+                .ops()
+                .last()
+                .map(|op| (op.old_range().start, op.new_range().start))
+                .unwrap_or_default();
+
+            let digit_with = OneIndexed::from_zero_indexed(largest_new.max(largest_old)).digits();
+
+            if let Some(cell) = cell {
+                // Room for 2 digits, 2 x 1 space before each digit, 1 space, and 1 `|`. This
+                // centers the three colons on the pipe.
+                writeln!(f, "{:>1$} cell {cell}", ":::", 2 * digit_with.get() + 4)?;
+            }
+
+            for (idx, group) in diff.grouped_ops(3).iter().enumerate() {
+                if idx > 0 {
+                    writeln!(f, "{:-^1$}", "-", 80)?;
+                }
+                for op in group {
+                    for change in diff.iter_inline_changes(op) {
+                        let sign = match change.tag() {
+                            ChangeTag::Delete => "-",
+                            ChangeTag::Insert => "+",
+                            ChangeTag::Equal => " ",
+                        };
+
+                        let line_style = LineStyle::from(change.tag(), self.stylesheet);
+
+                        let old_index = change.old_index().map(OneIndexed::from_zero_indexed);
+                        let new_index = change.new_index().map(OneIndexed::from_zero_indexed);
+
+                        write!(
+                            f,
+                            "{} {} |{}",
+                            Line {
+                                index: old_index,
+                                width: digit_with,
+                            },
+                            Line {
+                                index: new_index,
+                                width: digit_with,
+                            },
+                            fmt_styled(line_style.apply_to(sign), self.stylesheet.emphasis),
+                        )?;
+
+                        for (emphasized, value) in change.iter_strings_lossy() {
+                            let value = show_nonprinting(&value);
+                            if emphasized {
+                                write!(
+                                    f,
+                                    "{}",
+                                    fmt_styled(
+                                        line_style.apply_to(&value),
+                                        self.stylesheet.underline
+                                    )
+                                )?;
+                            } else {
+                                write!(f, "{}", line_style.apply_to(&value))?;
+                            }
+                        }
+                        if change.missing_newline() {
+                            writeln!(f)?;
+                        }
+                    }
+                }
+            }
+        }
+
+        Ok(())
+    }
+}
+
+struct LineStyle {
+    style: Style,
+}
+
+impl LineStyle {
+    fn apply_to(&self, input: &str) -> impl std::fmt::Display {
+        fmt_styled(input, self.style)
+    }
+
+    fn from(value: ChangeTag, stylesheet: &DiagnosticStylesheet) -> LineStyle {
+        match value {
+            ChangeTag::Equal => LineStyle {
+                style: stylesheet.none,
+            },
+            ChangeTag::Delete => LineStyle {
+                style: stylesheet.deletion,
+            },
+            ChangeTag::Insert => LineStyle {
+                style: stylesheet.insertion,
+            },
+        }
+    }
+}
+
+struct Line {
+    index: Option<OneIndexed>,
+    width: NonZeroUsize,
+}
+
+impl std::fmt::Display for Line {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self.index {
+            None => {
+                for _ in 0..self.width.get() {
+                    f.write_str(" ")?;
+                }
+                Ok(())
+            }
+            Some(idx) => write!(f, "{:<width$}", idx, width = self.width.get()),
+        }
+    }
+}
+
+fn show_nonprinting(s: &str) -> Cow<'_, str> {
+    if s.find(['\x07', '\x08', '\x1b', '\x7f']).is_some() {
+        Cow::Owned(
+            s.replace('\x07', "␇")
+                .replace('\x08', "␈")
+                .replace('\x1b', "␛")
+                .replace('\x7f', "␡"),
+        )
+    } else {
+        Cow::Borrowed(s)
+    }
+}
+
 #[cfg(test)]
 mod tests {
-    use ruff_diagnostics::Applicability;
-    use ruff_text_size::TextRange;
+    use ruff_diagnostics::{Applicability, Fix};
+    use ruff_text_size::{TextLen, TextRange, TextSize};

    use crate::diagnostic::{
        Annotation, DiagnosticFormat, Severity,
@@ -186,7 +483,7 @@ print()
    /// For example, without the fix, we get diagnostics like this:
    ///
    /// ```
-    /// error[invalid-character-sub]: Invalid unescaped character SUB, use "\x1A" instead
+    /// error[invalid-character-sub]: Invalid unescaped character SUB, use "\x1a" instead
    ///  --> example.py:1:25
    ///   |
    /// 1 | nested_fstrings = f'␈{f'{f'␛'}'}'
@@ -206,13 +503,13 @@ print()
            .builder(
                "invalid-character-sub",
                Severity::Error,
-                r#"Invalid unescaped character SUB, use "\x1A" instead"#,
+                r#"Invalid unescaped character SUB, use "\x1a" instead"#,
            )
            .primary("example.py", "1:24", "1:24", "")
            .build();

        insta::assert_snapshot!(env.render(&diagnostic), @r#"
-        error[invalid-character-sub]: Invalid unescaped character SUB, use "\x1A" instead
+        error[invalid-character-sub]: Invalid unescaped character SUB, use "\x1a" instead
         --> example.py:1:25
          |
        1 | nested_fstrings = f'␈{f'{f'␛'}'}'
@@ -231,13 +528,13 @@ print()
            .builder(
                "invalid-character-sub",
                Severity::Error,
-                r#"Invalid unescaped character SUB, use "\x1A" instead"#,
+                r#"Invalid unescaped character SUB, use "\x1a" instead"#,
            )
            .primary("example.py", "1:1", "1:1", "")
            .build();

        insta::assert_snapshot!(env.render(&diagnostic), @r#"
-        error[invalid-character-sub]: Invalid unescaped character SUB, use "\x1A" instead
+        error[invalid-character-sub]: Invalid unescaped character SUB, use "\x1a" instead
         --> example.py:1:2
          |
        1 | ␈␛
@@ -400,4 +697,208 @@ print()
        help: Remove `print` statement
        ");
    }
+
+    /// Test that we remap notebook cell line numbers in the diff as well as the main diagnostic.
+    #[test]
+    fn notebook_output_with_diff() {
+        let (mut env, diagnostics) = create_notebook_diagnostics(DiagnosticFormat::Full);
+        env.show_fix_diff(true);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        error[unused-import][*]: `os` imported but unused
+         --> notebook.ipynb:cell 1:2:8
+          |
+        1 | # cell 1
+        2 | import os
+          |        ^^
+          |
+        help: Remove unused import: `os`
+
+        ℹ Safe fix
+           ::: cell 1
+        1 1 | # cell 1
+        2   |-import os
+
+        error[unused-import][*]: `math` imported but unused
+         --> notebook.ipynb:cell 2:2:8
+          |
+        1 | # cell 2
+        2 | import math
+          |        ^^^^
+        3 |
+        4 | print('hello world')
+          |
+        help: Remove unused import: `math`
+
+        ℹ Safe fix
+           ::: cell 2
+        1 1 | # cell 2
+        2   |-import math
+        3 2 | 
+        4 3 | print('hello world')
+
+        error[unused-variable]: Local variable `x` is assigned to but never used
+         --> notebook.ipynb:cell 3:4:5
+          |
+        2 | def foo():
+        3 |     print()
+        4 |     x = 1
+          |     ^
+          |
+        help: Remove assignment to unused variable `x`
+
+        ℹ Unsafe fix
+           ::: cell 3
+        1 1 | # cell 3
+        2 2 | def foo():
+        3 3 |     print()
+        4   |-    x = 1
+        5 4 |
+        ");
+    }
+
+    #[test]
+    fn notebook_output_with_diff_spanning_cells() {
+        let (mut env, mut diagnostics) = create_notebook_diagnostics(DiagnosticFormat::Full);
+        env.show_fix_diff(true);
+
+        // Move all of the edits from the later diagnostics to the first diagnostic to simulate a
+        // single diagnostic with edits in different cells.
+        let mut diagnostic = diagnostics.swap_remove(0);
+        let fix = diagnostic.fix_mut().unwrap();
+        let mut edits = fix.edits().to_vec();
+        for diag in diagnostics {
+            edits.extend_from_slice(diag.fix().unwrap().edits());
+        }
+        *fix = Fix::unsafe_edits(edits.remove(0), edits);
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r"
+        error[unused-import]: `os` imported but unused
+         --> notebook.ipynb:cell 1:2:8
+          |
+        1 | # cell 1
+        2 | import os
+          |        ^^
+          |
+        help: Remove unused import: `os`
+
+        ℹ Unsafe fix
+           ::: cell 1
+        1 1 | # cell 1
+        2   |-import os
+           ::: cell 2
+        1 1 | # cell 2
+        2   |-import math
+        3 2 | 
+        4 3 | print('hello world')
+           ::: cell 3
+        1 1 | # cell 3
+        2 2 | def foo():
+        3 3 |     print()
+        4   |-    x = 1
+        5 4 |
+        ");
+    }
+
+    /// Carriage return (`\r`) is a valid line-ending in Python, so we should normalize this to a
+    /// line feed (`\n`) for rendering. Otherwise we report a single long line for this case.
+    #[test]
+    fn normalize_carriage_return() {
+        let mut env = TestEnvironment::new();
+        env.add(
+            "example.py",
+            "# Keep parenthesis around preserved CR\rint(-\r    1)\rint(+\r    1)",
+        );
+        env.format(DiagnosticFormat::Full);
+
+        let mut diagnostic = env.err().build();
+        let span = env
+            .path("example.py")
+            .with_range(TextRange::at(TextSize::new(39), TextSize::new(0)));
+        let annotation = Annotation::primary(span);
+        diagnostic.annotate(annotation);
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r"
+        error[test-diagnostic]: main diagnostic message
+         --> example.py:2:1
+          |
+        1 | # Keep parenthesis around preserved CR
+        2 | int(-
+          | ^
+        3 |     1)
+        4 | int(+
+          |
+        ");
+    }
+
+    /// Without stripping the BOM, we report an error in column 2, unlike Ruff.
+    #[test]
+    fn strip_bom() {
+        let mut env = TestEnvironment::new();
+        env.add("example.py", "\u{feff}import foo");
+        env.format(DiagnosticFormat::Full);
+
+        let mut diagnostic = env.err().build();
+        let span = env
+            .path("example.py")
+            .with_range(TextRange::at(TextSize::new(3), TextSize::new(0)));
+        let annotation = Annotation::primary(span);
+        diagnostic.annotate(annotation);
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r"
+        error[test-diagnostic]: main diagnostic message
+         --> example.py:1:1
+          |
+        1 | import foo
+          | ^
+          |
+        ");
+    }
+
+    #[test]
+    fn bom_with_default_range() {
+        let mut env = TestEnvironment::new();
+        env.add("example.py", "\u{feff}import foo");
+        env.format(DiagnosticFormat::Full);
+
+        let mut diagnostic = env.err().build();
+        let span = env.path("example.py").with_range(TextRange::default());
+        let annotation = Annotation::primary(span);
+        diagnostic.annotate(annotation);
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r"
+        error[test-diagnostic]: main diagnostic message
+         --> example.py:1:1
+          |
+        1 | import foo
+          | ^
+          |
+        ");
+    }
+
+    /// We previously rendered this correctly, but the header was falling back to 1:1 for ranges
+    /// pointing to the final newline in a file. Like Ruff, we now use the offset of the first
+    /// character in the nonexistent final line in the header.
+    #[test]
+    fn end_of_file() {
+        let mut env = TestEnvironment::new();
+        let contents = "unexpected eof\n";
+        env.add("example.py", contents);
+        env.format(DiagnosticFormat::Full);
+
+        let mut diagnostic = env.err().build();
+        let span = env
+            .path("example.py")
+            .with_range(TextRange::at(contents.text_len(), TextSize::new(0)));
+        let annotation = Annotation::primary(span);
+        diagnostic.annotate(annotation);
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r"
+        error[test-diagnostic]: main diagnostic message
+         --> example.py:2:1
+          |
+        1 | unexpected eof
+          |               ^
+          |
+        ");
+    }
 }
--- a/crates/ruff_db/src/diagnostic/render/gitlab.rs
+++ b/crates/ruff_db/src/diagnostic/render/gitlab.rs
@@ -0,0 +1,205 @@
+use std::{
+    collections::HashSet,
+    hash::{DefaultHasher, Hash, Hasher},
+    path::Path,
+};
+
+use ruff_source_file::LineColumn;
+use serde::{Serialize, Serializer, ser::SerializeSeq};
+
+use crate::diagnostic::{Diagnostic, Severity};
+
+use super::FileResolver;
+
+pub(super) struct GitlabRenderer<'a> {
+    resolver: &'a dyn FileResolver,
+}
+
+impl<'a> GitlabRenderer<'a> {
+    pub(super) fn new(resolver: &'a dyn FileResolver) -> Self {
+        Self { resolver }
+    }
+}
+
+impl GitlabRenderer<'_> {
+    pub(super) fn render(
+        &self,
+        f: &mut std::fmt::Formatter,
+        diagnostics: &[Diagnostic],
+    ) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            serde_json::to_string_pretty(&SerializedMessages {
+                diagnostics,
+                resolver: self.resolver,
+                #[expect(
+                    clippy::disallowed_methods,
+                    reason = "We don't have access to a `System` here, \
+                              and this is only intended for use by GitLab CI, \
+                              which runs on a real `System`."
+                )]
+                project_dir: std::env::var("CI_PROJECT_DIR").ok().as_deref(),
+            })
+            .unwrap()
+        )
+    }
+}
+
+struct SerializedMessages<'a> {
+    diagnostics: &'a [Diagnostic],
+    resolver: &'a dyn FileResolver,
+    project_dir: Option<&'a str>,
+}
+
+impl Serialize for SerializedMessages<'_> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut s = serializer.serialize_seq(Some(self.diagnostics.len()))?;
+        let mut fingerprints = HashSet::<u64>::with_capacity(self.diagnostics.len());
+
+        for diagnostic in self.diagnostics {
+            let location = diagnostic
+                .primary_span()
+                .map(|span| {
+                    let file = span.file();
+                    let positions = if self.resolver.is_notebook(file) {
+                        // We can't give a reasonable location for the structured formats,
+                        // so we show one that's clearly a fallback
+                        Default::default()
+                    } else {
+                        let diagnostic_source = file.diagnostic_source(self.resolver);
+                        let source_code = diagnostic_source.as_source_code();
+                        span.range()
+                            .map(|range| Positions {
+                                begin: source_code.line_column(range.start()),
+                                end: source_code.line_column(range.end()),
+                            })
+                            .unwrap_or_default()
+                    };
+
+                    let path = self.project_dir.as_ref().map_or_else(
+                        || file.relative_path(self.resolver).display().to_string(),
+                        |project_dir| relativize_path_to(file.path(self.resolver), project_dir),
+                    );
+
+                    Location { path, positions }
+                })
+                .unwrap_or_default();
+
+            let mut message_fingerprint = fingerprint(diagnostic, &location.path, 0);
+
+            // Make sure that we do not get a fingerprint that is already in use
+            // by adding in the previously generated one.
+            while fingerprints.contains(&message_fingerprint) {
+                message_fingerprint = fingerprint(diagnostic, &location.path, message_fingerprint);
+            }
+            fingerprints.insert(message_fingerprint);
+
+            let description = diagnostic.body();
+            let check_name = diagnostic.secondary_code_or_id();
+            let severity = match diagnostic.severity() {
+                Severity::Info => "info",
+                Severity::Warning => "minor",
+                Severity::Error => "major",
+                // Another option here is `blocker`
+                Severity::Fatal => "critical",
+            };
+
+            let value = Message {
+                check_name,
+                // GitLab doesn't display the separate `check_name` field in a Code Quality report,
+                // so prepend it to the description too.
+                description: format!("{check_name}: {description}"),
+                severity,
+                fingerprint: format!("{:x}", message_fingerprint),
+                location,
+            };
+
+            s.serialize_element(&value)?;
+        }
+
+        s.end()
+    }
+}
+
+#[derive(Serialize)]
+struct Message<'a> {
+    check_name: &'a str,
+    description: String,
+    severity: &'static str,
+    fingerprint: String,
+    location: Location,
+}
+
+/// The place in the source code where the issue was discovered.
+///
+/// According to the CodeClimate report format [specification] linked from the GitLab [docs], this
+/// field is required, so we fall back on a default `path` and position if the diagnostic doesn't
+/// have a primary span.
+///
+/// [specification]: https://github.com/codeclimate/platform/blob/master/spec/analyzers/SPEC.md#data-types
+/// [docs]: https://docs.gitlab.com/ci/testing/code_quality/#code-quality-report-format
+#[derive(Default, Serialize)]
+struct Location {
+    path: String,
+    positions: Positions,
+}
+
+#[derive(Default, Serialize)]
+struct Positions {
+    begin: LineColumn,
+    end: LineColumn,
+}
+
+/// Generate a unique fingerprint to identify a violation.
+fn fingerprint(diagnostic: &Diagnostic, project_path: &str, salt: u64) -> u64 {
+    let mut hasher = DefaultHasher::new();
+
+    salt.hash(&mut hasher);
+    diagnostic.name().hash(&mut hasher);
+    project_path.hash(&mut hasher);
+
+    hasher.finish()
+}
+
+/// Convert an absolute path to be relative to the specified project root.
+fn relativize_path_to<P: AsRef<Path>, R: AsRef<Path>>(path: P, project_root: R) -> String {
+    format!(
+        "{}",
+        pathdiff::diff_paths(&path, project_root)
+            .expect("Could not diff paths")
+            .display()
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::diagnostic::{
+        DiagnosticFormat,
+        render::tests::{create_diagnostics, create_syntax_error_diagnostics},
+    };
+
+    const FINGERPRINT_FILTERS: [(&str, &str); 1] = [(
+        r#""fingerprint": "[a-z0-9]+","#,
+        r#""fingerprint": "<redacted>","#,
+    )];
+
+    #[test]
+    fn output() {
+        let (env, diagnostics) = create_diagnostics(DiagnosticFormat::Gitlab);
+        insta::with_settings!({filters => FINGERPRINT_FILTERS}, {
+            insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
+        });
+    }
+
+    #[test]
+    fn syntax_errors() {
+        let (env, diagnostics) = create_syntax_error_diagnostics(DiagnosticFormat::Gitlab);
+        insta::with_settings!({filters => FINGERPRINT_FILTERS}, {
+            insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
+        });
+    }
+}
--- a/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrendergitlabtests__output.snap
+++ b/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrendergitlabtests__output.snap
@@ -0,0 +1,63 @@
+---
+source: crates/ruff_db/src/diagnostic/render/gitlab.rs
+expression: env.render_diagnostics(&diagnostics)
+---
+[
+  {
+    "check_name": "F401",
+    "description": "F401: `os` imported but unused",
+    "severity": "major",
+    "fingerprint": "<redacted>",
+    "location": {
+      "path": "fib.py",
+      "positions": {
+        "begin": {
+          "line": 1,
+          "column": 8
+        },
+        "end": {
+          "line": 1,
+          "column": 10
+        }
+      }
+    }
+  },
+  {
+    "check_name": "F841",
+    "description": "F841: Local variable `x` is assigned to but never used",
+    "severity": "major",
+    "fingerprint": "<redacted>",
+    "location": {
+      "path": "fib.py",
+      "positions": {
+        "begin": {
+          "line": 6,
+          "column": 5
+        },
+        "end": {
+          "line": 6,
+          "column": 6
+        }
+      }
+    }
+  },
+  {
+    "check_name": "F821",
+    "description": "F821: Undefined name `a`",
+    "severity": "major",
+    "fingerprint": "<redacted>",
+    "location": {
+      "path": "undef.py",
+      "positions": {
+        "begin": {
+          "line": 1,
+          "column": 4
+        },
+        "end": {
+          "line": 1,
+          "column": 5
+        }
+      }
+    }
+  }
+]
--- a/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrendergitlabtests__syntax_errors.snap
+++ b/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrendergitlabtests__syntax_errors.snap
@@ -0,0 +1,44 @@
+---
+source: crates/ruff_db/src/diagnostic/render/gitlab.rs
+expression: env.render_diagnostics(&diagnostics)
+---
+[
+  {
+    "check_name": "invalid-syntax",
+    "description": "invalid-syntax: Expected one or more symbol names after import",
+    "severity": "major",
+    "fingerprint": "<redacted>",
+    "location": {
+      "path": "syntax_errors.py",
+      "positions": {
+        "begin": {
+          "line": 1,
+          "column": 15
+        },
+        "end": {
+          "line": 2,
+          "column": 1
+        }
+      }
+    }
+  },
+  {
+    "check_name": "invalid-syntax",
+    "description": "invalid-syntax: Expected ')', found newline",
+    "severity": "major",
+    "fingerprint": "<redacted>",
+    "location": {
+      "path": "syntax_errors.py",
+      "positions": {
+        "begin": {
+          "line": 3,
+          "column": 12
+        },
+        "end": {
+          "line": 4,
+          "column": 1
+        }
+      }
+    }
+  }
+]
--- a/crates/ruff_db/src/diagnostic/stylesheet.rs
+++ b/crates/ruff_db/src/diagnostic/stylesheet.rs
@@ -40,9 +40,12 @@ pub struct DiagnosticStylesheet {
    pub(crate) help: Style,
    pub(crate) line_no: Style,
    pub(crate) emphasis: Style,
+    pub(crate) underline: Style,
    pub(crate) none: Style,
    pub(crate) separator: Style,
    pub(crate) secondary_code: Style,
+    pub(crate) insertion: Style,
+    pub(crate) deletion: Style,
 }

 impl Default for DiagnosticStylesheet {
@@ -63,9 +66,12 @@ impl DiagnosticStylesheet {
            help: AnsiColor::BrightCyan.on_default().effects(Effects::BOLD),
            line_no: bright_blue.effects(Effects::BOLD),
            emphasis: Style::new().effects(Effects::BOLD),
+            underline: Style::new().effects(Effects::UNDERLINE),
            none: Style::new(),
            separator: AnsiColor::Cyan.on_default(),
            secondary_code: AnsiColor::Red.on_default().effects(Effects::BOLD),
+            insertion: AnsiColor::Green.on_default(),
+            deletion: AnsiColor::Red.on_default(),
        }
    }

@@ -78,9 +84,12 @@ impl DiagnosticStylesheet {
            help: Style::new(),
            line_no: Style::new(),
            emphasis: Style::new(),
+            underline: Style::new(),
            none: Style::new(),
            separator: Style::new(),
            secondary_code: Style::new(),
+            insertion: Style::new(),
+            deletion: Style::new(),
        }
    }
 }
--- a/crates/ruff_db/src/file_revision.rs
+++ b/crates/ruff_db/src/file_revision.rs
@@ -9,7 +9,7 @@ use crate::system::file_time_now;
 /// * The last modification time of the file.
 /// * The hash of the file's content.
 /// * The revision as it comes from an external system, for example the LSP.
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Default)]
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Default, get_size2::GetSize)]
 pub struct FileRevision(u128);

 impl FileRevision {
--- a/crates/ruff_db/src/files.rs
+++ b/crates/ruff_db/src/files.rs
@@ -87,11 +87,12 @@ impl Files {
            .system_by_path
            .entry(absolute.clone())
            .or_insert_with(|| {
-                tracing::trace!("Adding file '{path}'");
-
                let metadata = db.system().path_metadata(path);
+
+                tracing::trace!("Adding file '{absolute}'");
+
                let durability = self
-                    .root(db, path)
+                    .root(db, &absolute)
                    .map_or(Durability::default(), |root| root.durability(db));

                let builder = File::builder(FilePath::System(absolute))
@@ -289,7 +290,7 @@ impl std::panic::RefUnwindSafe for Files {}
 /// # Ordering
 /// Ordering is based on the file's salsa-assigned id and not on its values.
 /// The id may change between runs.
-#[salsa::input]
+#[salsa::input(heap_size=ruff_memory_usage::heap_size)]
 #[derive(PartialOrd, Ord)]
 pub struct File {
    /// The path of the file (immutable).
@@ -521,7 +522,7 @@ impl VirtualFile {
 // The types in here need to be public because they're salsa ingredients but we
 // don't want them to be publicly accessible. That's why we put them into a private module.
 mod private {
-    #[derive(Copy, Clone, Debug, Eq, PartialEq, Default)]
+    #[derive(Copy, Clone, Debug, Eq, PartialEq, Default, get_size2::GetSize)]
    pub enum FileStatus {
        /// The file exists.
        #[default]
--- a/crates/ruff_db/src/files/file_root.rs
+++ b/crates/ruff_db/src/files/file_root.rs
@@ -16,7 +16,7 @@ use crate::system::{SystemPath, SystemPathBuf};
 /// The main usage of file roots is to determine a file's durability. But it can also be used
 /// to make a salsa query dependent on whether a file in a root has changed without writing any
 /// manual invalidation logic.
-#[salsa::input(debug)]
+#[salsa::input(debug, heap_size=ruff_memory_usage::heap_size)]
 pub struct FileRoot {
    /// The path of a root is guaranteed to never change.
    #[returns(deref)]
@@ -37,7 +37,7 @@ impl FileRoot {
    }
 }

-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[derive(Copy, Clone, Debug, Eq, PartialEq, get_size2::GetSize)]
 pub enum FileRootKind {
    /// The root of a project.
    Project,
--- a/crates/ruff_db/src/files/path.rs
+++ b/crates/ruff_db/src/files/path.rs
@@ -11,7 +11,7 @@ use std::fmt::{Display, Formatter};
 /// * a file stored on the [host system](crate::system::System).
 /// * a virtual file stored on the [host system](crate::system::System).
 /// * a vendored file stored in the [vendored file system](crate::vendored::VendoredFileSystem).
-#[derive(Clone, Debug, Eq, PartialEq, Hash)]
+#[derive(Clone, Debug, Eq, PartialEq, Hash, get_size2::GetSize)]
 pub enum FilePath {
    /// Path to a file on the [host system](crate::system::System).
    System(SystemPathBuf),
--- a/crates/ruff_db/src/lib.rs
+++ b/crates/ruff_db/src/lib.rs
@@ -1,3 +1,8 @@
+#![warn(
+    clippy::disallowed_methods,
+    reason = "Prefer System trait methods over std methods"
+)]
+
 use crate::files::Files;
 use crate::system::System;
 use crate::vendored::VendoredFileSystem;
@@ -65,6 +70,10 @@ pub trait Db: salsa::Database {
 /// to process work in parallel. For example, to index a directory or checking the files of a project.
 /// ty can still spawn more threads for other tasks, e.g. to wait for a Ctrl+C signal or
 /// watching the files for changes.
+#[expect(
+    clippy::disallowed_methods,
+    reason = "We don't have access to System here, but this is also only used by the CLI and the server which always run on a real system."
+)]
 pub fn max_parallelism() -> NonZeroUsize {
    std::env::var(EnvVars::TY_MAX_PARALLELISM)
        .or_else(|_| std::env::var(EnvVars::RAYON_NUM_THREADS))
--- a/crates/ruff_db/src/parsed.rs
+++ b/crates/ruff_db/src/parsed.rs
@@ -92,14 +92,14 @@ impl ParsedModule {
        self.inner.store(None);
    }

-    /// Returns a pointer for this [`ParsedModule`].
+    /// Returns the pointer address of this [`ParsedModule`].
    ///
    /// The pointer uniquely identifies the module within the current Salsa revision,
    /// regardless of whether particular [`ParsedModuleRef`] instances are garbage collected.
-    pub fn as_ptr(&self) -> *const () {
+    pub fn addr(&self) -> usize {
        // Note that the outer `Arc` in `inner` is stable across garbage collection, while the inner
        // `Arc` within the `ArcSwap` may change.
-        Arc::as_ptr(&self.inner).cast()
+        Arc::as_ptr(&self.inner).addr()
    }
 }

@@ -202,9 +202,13 @@ mod indexed {

        /// Returns the node at the given index.
        pub fn get_by_index<'ast>(&'ast self, index: NodeIndex) -> AnyRootNodeRef<'ast> {
+            let index = index
+                .as_u32()
+                .expect("attempted to access uninitialized `NodeIndex`");
+
            // Note that this method restores the correct lifetime: the nodes are valid for as
            // long as the reference to `IndexedModule` is alive.
-            self.index[index.as_usize()]
+            self.index[index as usize]
        }
    }

@@ -220,7 +224,7 @@ mod indexed {
            T: HasNodeIndex + std::fmt::Debug,
            AnyRootNodeRef<'a>: From<&'a T>,
        {
-            node.node_index().set(self.index);
+            node.node_index().set(NodeIndex::from(self.index));
            self.nodes.push(AnyRootNodeRef::from(node));
            self.index += 1;
        }
--- a/crates/ruff_db/src/system.rs
+++ b/crates/ruff_db/src/system.rs
@@ -46,7 +46,7 @@ pub type Result<T> = std::io::Result<T>;
 ///    * File watching isn't supported.
 ///
 /// Abstracting the system also enables tests to use a more efficient in-memory file system.
-pub trait System: Debug {
+pub trait System: Debug + Sync + Send {
    /// Reads the metadata of the file or directory at `path`.
    ///
    /// This function will traverse symbolic links to query information about the destination file.
@@ -197,6 +197,8 @@ pub trait System: Debug {
    fn as_any(&self) -> &dyn std::any::Any;

    fn as_any_mut(&mut self) -> &mut dyn std::any::Any;
+
+    fn dyn_clone(&self) -> Box<dyn System>;
 }

 #[derive(Debug, Default, Copy, Clone, Eq, PartialEq)]
--- a/crates/ruff_db/src/system/os.rs
+++ b/crates/ruff_db/src/system/os.rs
@@ -1,3 +1,5 @@
+#![allow(clippy::disallowed_methods)]
+
 use super::walk_directory::{
    self, DirectoryWalker, WalkDirectoryBuilder, WalkDirectoryConfiguration,
    WalkDirectoryVisitorBuilder, WalkState,
@@ -255,6 +257,10 @@ impl System for OsSystem {
    fn env_var(&self, name: &str) -> std::result::Result<String, std::env::VarError> {
        std::env::var(name)
    }
+
+    fn dyn_clone(&self) -> Box<dyn System> {
+        Box::new(self.clone())
+    }
 }

 impl OsSystem {
--- a/crates/ruff_db/src/system/path.rs
+++ b/crates/ruff_db/src/system/path.rs
@@ -762,7 +762,7 @@ impl SystemVirtualPath {
 }

 /// An owned, virtual path on [`System`](`super::System`) (akin to [`String`]).
-#[derive(Eq, PartialEq, Clone, Hash, PartialOrd, Ord)]
+#[derive(Eq, PartialEq, Clone, Hash, PartialOrd, Ord, get_size2::GetSize)]
 pub struct SystemVirtualPathBuf(String);

 impl SystemVirtualPathBuf {
--- a/crates/ruff_db/src/system/test.rs
+++ b/crates/ruff_db/src/system/test.rs
@@ -146,6 +146,10 @@ impl System for TestSystem {
    fn case_sensitivity(&self) -> CaseSensitivity {
        self.system().case_sensitivity()
    }
+
+    fn dyn_clone(&self) -> Box<dyn System> {
+        Box::new(self.clone())
+    }
 }

 impl Default for TestSystem {
@@ -394,6 +398,13 @@ impl System for InMemorySystem {
    fn case_sensitivity(&self) -> CaseSensitivity {
        CaseSensitivity::CaseSensitive
    }
+
+    fn dyn_clone(&self) -> Box<dyn System> {
+        Box::new(Self {
+            user_config_directory: Mutex::new(self.user_config_directory.lock().unwrap().clone()),
+            memory_fs: self.memory_fs.clone(),
+        })
+    }
 }

 impl WritableSystem for InMemorySystem {
--- a/crates/ruff_dev/Cargo.toml
+++ b/crates/ruff_dev/Cargo.toml
@@ -13,6 +13,7 @@ license = { workspace = true }
 [dependencies]
 ty = { workspace = true }
 ty_project = { workspace = true, features = ["schemars"] }
+ty_python_semantic = { workspace = true }
 ty_static = { workspace = true }
 ruff = { workspace = true }
 ruff_formatter = { workspace = true }
--- a/crates/ruff_dev/src/generate_ty_rules.rs
+++ b/crates/ruff_dev/src/generate_ty_rules.rs
@@ -52,7 +52,7 @@ pub(crate) fn main(args: &Args) -> Result<()> {
 }

 fn generate_markdown() -> String {
-    let registry = &*ty_project::DEFAULT_LINT_REGISTRY;
+    let registry = ty_python_semantic::default_lint_registry();

    let mut output = String::new();

--- a/crates/ruff_diagnostics/Cargo.toml
+++ b/crates/ruff_diagnostics/Cargo.toml
@@ -14,8 +14,11 @@ license = { workspace = true }
 doctest = false

 [dependencies]
-ruff_text_size = { workspace = true }
+ruff_text_size = { workspace = true, features = ["get-size"] }

 get-size2 = { workspace = true }
 is-macro = { workspace = true }
 serde = { workspace = true, optional = true, features = [] }
+
+[features]
+serde = ["dep:serde", "ruff_text_size/serde"]
--- a/crates/ruff_linter/Cargo.toml
+++ b/crates/ruff_linter/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ruff_linter"
-version = "0.12.8"
+version = "0.12.11"
 publish = false
 authors = { workspace = true }
 edition = { workspace = true }
@@ -13,7 +13,6 @@ license = { workspace = true }
 [lib]

 [dependencies]
-ruff_annotate_snippets = { workspace = true }
 ruff_cache = { workspace = true }
 ruff_db = { workspace = true, features = ["junit", "serde"] }
 ruff_diagnostics = { workspace = true, features = ["serde"] }
@@ -52,7 +51,6 @@ path-absolutize = { workspace = true, features = [
    "once_cell_cache",
    "use_unix_paths_on_wasm",
 ] }
-pathdiff = { workspace = true }
 pep440_rs = { workspace = true }
 pyproject-toml = { workspace = true }
 regex = { workspace = true }
--- a/crates/ruff_linter/resources/test/fixtures/airflow/AIR301_names.py
+++ b/crates/ruff_linter/resources/test/fixtures/airflow/AIR301_names.py
@@ -13,6 +13,7 @@ from airflow.api_connexion.security import requires_access
 from airflow.contrib.aws_athena_hook import AWSAthenaHook
 from airflow.datasets import DatasetAliasEvent
 from airflow.operators.subdag import SubDagOperator
+from airflow.secrets.cache import SecretCache
 from airflow.secrets.local_filesystem import LocalFilesystemBackend
 from airflow.triggers.external_task import TaskStateTrigger
 from airflow.utils import dates
@@ -56,6 +57,9 @@ SubDagOperator()
 # get_connection
 LocalFilesystemBackend()

+# airflow.secrets.cache
+SecretCache()
+

 # airflow.triggers.external_task
 TaskStateTrigger()
--- a/crates/ruff_linter/resources/test/fixtures/airflow/AIR311_names.py
+++ b/crates/ruff_linter/resources/test/fixtures/airflow/AIR311_names.py
@@ -34,7 +34,7 @@ task_group()
 setup()
 from airflow.decorators import teardown
 from airflow.io.path import ObjectStoragePath
-from airflow.io.storage import attach
+from airflow.io.store import attach
 from airflow.models import DAG as DAGFromModel
 from airflow.models import (
    Connection,
@@ -74,3 +74,36 @@ DatasetOrTimeSchedule()

 # airflow.utils.dag_parsing_context
 get_parsing_context()
+
+from airflow.decorators.base import (
+    DecoratedMappedOperator,
+    DecoratedOperator,
+    TaskDecorator,
+    get_unique_task_id,
+    task_decorator_factory,
+)
+
+# airflow.decorators.base
+DecoratedMappedOperator()
+DecoratedOperator()
+TaskDecorator()
+get_unique_task_id()
+task_decorator_factory()
+
+
+from airflow.models import Param
+
+# airflow.models
+Param()
+
+
+from airflow.sensors.base import (
+    BaseSensorOperator,
+    PokeReturnValue,
+    poke_mode_only,
+)
+
+# airflow.sensors.base
+BaseSensorOperator()
+PokeReturnValue()
+poke_mode_only()
--- a/crates/ruff_linter/resources/test/fixtures/airflow/AIR312.py
+++ b/crates/ruff_linter/resources/test/fixtures/airflow/AIR312.py
@@ -9,7 +9,6 @@ from airflow.operators.empty import EmptyOperator
 from airflow.operators.latest_only import LatestOnlyOperator
 from airflow.operators.trigger_dagrun import TriggerDagRunOperator
 from airflow.operators.weekday import BranchDayOfWeekOperator
-from airflow.sensors.date_time import DateTimeSensor

 FSHook()
 PackageIndexHook()
@@ -22,7 +21,6 @@ EmptyOperator()

 LatestOnlyOperator()
 BranchDayOfWeekOperator()
-DateTimeSensor()

 from airflow.operators.python import (
    BranchPythonOperator,
@@ -30,16 +28,23 @@ from airflow.operators.python import (
    PythonVirtualenvOperator,
    ShortCircuitOperator,
 )
+from airflow.sensors.bash import BashSensor
+from airflow.sensors.date_time import DateTimeSensor
+
+BranchPythonOperator()
+PythonOperator()
+PythonVirtualenvOperator()
+ShortCircuitOperator()
+
+BashSensor()
+DateTimeSensor()
 from airflow.sensors.date_time import DateTimeSensorAsync
 from airflow.sensors.external_task import (
    ExternalTaskMarker,
    ExternalTaskSensor,
 )
-from airflow.sensors.time_sensor import (
-    TimeSensor,
-    TimeSensorAsync,
-)
 from airflow.sensors.filesystem import FileSensor
+from airflow.sensors.python import PythonSensor

 BranchPythonOperator()
 PythonOperator()
@@ -49,6 +54,13 @@ DateTimeSensorAsync()
 ExternalTaskMarker()
 ExternalTaskSensor()
 FileSensor()
+PythonSensor()
+
+from airflow.sensors.time_sensor import (
+    TimeSensor,
+    TimeSensorAsync,
+)
+
 TimeSensor()
 TimeSensorAsync()

--- a/crates/ruff_linter/resources/test/fixtures/flake8_async/ASYNC212.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_async/ASYNC212.py
@@ -0,0 +1,75 @@
+from typing import Optional
+
+import httpx
+
+
+def foo():
+    client = httpx.Client()
+    client.close()  # Ok
+    client.delete()  # Ok
+    client.get()  # Ok
+    client.head()  # Ok
+    client.options()  # Ok
+    client.patch()  # Ok
+    client.post()  # Ok
+    client.put()  # Ok
+    client.request()  # Ok
+    client.send()  # Ok
+    client.stream()  # Ok
+
+    client.anything()  # Ok
+    client.build_request()  # Ok
+    client.is_closed  # Ok
+
+
+async def foo():
+    client = httpx.Client()
+    client.close()  # ASYNC212
+    client.delete()  # ASYNC212
+    client.get()  # ASYNC212
+    client.head()  # ASYNC212
+    client.options()  # ASYNC212
+    client.patch()  # ASYNC212
+    client.post()  # ASYNC212
+    client.put()  # ASYNC212
+    client.request()  # ASYNC212
+    client.send()  # ASYNC212
+    client.stream()  # ASYNC212
+
+    client.anything()  # Ok
+    client.build_request()  # Ok
+    client.is_closed  # Ok
+
+
+async def foo(client: httpx.Client):
+    client.request()  # ASYNC212
+    client.anything()  # Ok
+
+
+async def foo(client: httpx.Client | None):
+    client.request()  # ASYNC212
+    client.anything()  # Ok
+
+
+async def foo(client: Optional[httpx.Client]):
+    client.request()  # ASYNC212
+    client.anything()  # Ok
+
+
+async def foo():
+    client: httpx.Client = ...
+    client.request()  # ASYNC212
+    client.anything()  # Ok
+
+
+global_client = httpx.Client()
+
+
+async def foo():
+    global_client.request()  # ASYNC212
+    global_client.anything()  # Ok
+
+
+async def foo():
+    async with httpx.AsyncClient() as client:
+        await client.get()  # Ok
--- a/crates/ruff_linter/resources/test/fixtures/flake8_blind_except/BLE.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_blind_except/BLE.py
@@ -154,6 +154,11 @@ try:
 except Exception as e:
    raise ValueError from e

+try:
+    ...
+except Exception as e:
+    raise e from ValueError("hello")
+

 try:
    pass
@@ -245,3 +250,9 @@ try:
    pass
 except (Exception, ValueError) as e:
    raise e
+
+# `from None` cause
+try:
+    pass
+except BaseException as e:
+    raise e from None
--- a/crates/ruff_linter/resources/test/fixtures/flake8_comprehensions/C420_3.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_comprehensions/C420_3.py
@@ -0,0 +1,43 @@
+class C: a = None
+{C.a: None for C.a in "abc"}
+print(C.a)
+
+x = [None]
+{x[0]: None for x[0] in "abc"}
+print(x)
+
+class C(list):
+    def __getitem__(self, index, /):
+        item = super().__getitem__(index)
+        if isinstance(index, slice): item = tuple(item)
+        return item
+x = C()
+{x[:0]: None for x[:0] in "abc"}
+print(x)
+
+
+class C:
+    a = None
+
+def func():
+    {(C.a,): None for (C.a,) in "abc"}  # OK
+
+
+def func():
+    obj = type('obj', (), {'attr': 1})()
+    {(obj.attr,): None for (obj.attr,) in "abc"}  # OK
+
+
+def func():
+    lst = [1, 2, 3]
+    {(lst[0],): None for (lst[0],) in "abc"}  # OK
+
+
+def func():
+    lst = [1, 2, 3, 4, 5]
+    {(lst[1:3],): None for (lst[1:3],) in "abc"}  # OK
+
+
+# C420: side-effecting assignment targets
+# These should NOT trigger C420 because they have side-effecting assignment targets
+# See https://github.com/astral-sh/ruff/issues/19511
--- a/crates/ruff_linter/resources/test/fixtures/flake8_logging_format/G004.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_logging_format/G004.py
@@ -17,3 +17,50 @@ info(f"{__name__}")
 # Don't trigger for t-strings
 info(t"{name}")
 info(t"{__name__}")
+
+count = 5
+total = 9
+directory_path = "/home/hamir/ruff/crates/ruff_linter/resources/test/"
+logging.info(f"{count} out of {total} files in {directory_path} checked")
+
+
+
+x = 99
+fmt = "08d"
+logger.info(f"{x:{'08d'}}")
+logger.info(f"{x:>10} {x:{fmt}}")
+
+logging.info(f"")
+logging.info(f"This message doesn't have any variables.")
+
+obj = {"key": "value"}
+logging.info(f"Object: {obj!r}")
+
+items_count = 3
+logging.warning(f"Items: {items_count:d}")
+
+data = {"status": "active"}
+logging.info(f"Processing {len(data)} items")
+logging.info(f"Status: {data.get('status', 'unknown').upper()}")
+
+
+result = 123
+logging.info(f"Calculated result: {result + 100}")
+
+temperature = 123
+logging.info(f"Temperature: {temperature:.1f}°C")
+
+class FilePath:
+    def __init__(self, name: str):
+        self.name = name
+
+logging.info(f"No changes made to {file_path.name}.")
+
+user = "tron"
+balance = 123.45
+logging.error(f"Error {404}: User {user} has insufficient balance ${balance:.2f}")
+
+import logging
+
+x = 1
+logging.error(f"{x} -> %s", x)
--- a/crates/ruff_linter/resources/test/fixtures/flake8_logging_format/G004_arg_order.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_logging_format/G004_arg_order.py
@@ -0,0 +1,10 @@
+"""Test f-string argument order."""
+
+import logging
+
+logger = logging.getLogger(__name__)
+
+X = 1
+Y = 2
+logger.error(f"{X} -> %s", Y)
+logger.error(f"{Y} -> %s", X)
--- a/crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM905.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM905.py
@@ -161,3 +161,12 @@ r"""first
 'no need' to escape
 "swap" quote style
 "use' ugly triple quotes""".split("\n")
+
+# https://github.com/astral-sh/ruff/issues/19845
+print("S\x1cP\x1dL\x1eI\x1fT".split())
+print("\x1c\x1d\x1e\x1f>".split(maxsplit=0))
+print("<\x1c\x1d\x1e\x1f".rsplit(maxsplit=0))
+
+# leading/trailing whitespace should not count towards maxsplit
+" a b c d ".split(maxsplit=2)  # ["a", "b", "c d "]
+" a b c d ".rsplit(maxsplit=2)  # [" a b", "c", "d"]
--- a/crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/PTH211.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/PTH211.py
@@ -13,3 +13,11 @@ Path("tmp/python").symlink_to("usr/bin/python", target_is_directory=True)  # Ok
 fd = os.open(".", os.O_RDONLY)
 os.symlink("source.txt", "link.txt", dir_fd=fd)  # Ok: dir_fd is not supported by pathlib
 os.close(fd)
+
+os.symlink(src="usr/bin/python", dst="tmp/python", unknown=True)
+os.symlink("usr/bin/python",  dst="tmp/python", target_is_directory=False)
+
+os.symlink(src="usr/bin/python", dst="tmp/python", dir_fd=None)
+
+os.symlink("usr/bin/python",  dst="tmp/python", target_is_directory=     True    )
+os.symlink("usr/bin/python",  dst="tmp/python", target_is_directory="nonboolean")
--- a/crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/full_name.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/full_name.py
@@ -106,4 +106,22 @@ os.replace("src", "dst", src_dir_fd=1)
 os.replace("src", "dst", dst_dir_fd=2)

 os.getcwd()
-os.getcwdb()
+os.getcwdb()
+
+os.mkdir(path="directory")
+
+os.mkdir(
+    # comment 1
+    "directory",
+    mode=0o777
+)
+
+os.mkdir("directory", mode=0o777, dir_fd=1)
+
+os.makedirs("name", 0o777, exist_ok=False)
+
+os.makedirs("name", 0o777, False)
+
+os.makedirs(name="name", mode=0o777, exist_ok=False)
+
+os.makedirs("name", unknown_kwarg=True)
--- a/crates/ruff_linter/resources/test/fixtures/isort/required_imports/docstring_with_multiple_continuations.py
+++ b/crates/ruff_linter/resources/test/fixtures/isort/required_imports/docstring_with_multiple_continuations.py
@@ -0,0 +1,4 @@
+"""Hello, world!"""\
+\
+
+x = 1; y = 2
--- a/crates/ruff_linter/resources/test/fixtures/pyflakes/F401_35.py
+++ b/crates/ruff_linter/resources/test/fixtures/pyflakes/F401_35.py
@@ -0,0 +1,16 @@
+"""
+Test: allowed-unused-imports-top-level-module
+"""
+
+# No errors
+
+def f():
+    import hvplot
+def f():
+    import hvplot.pandas
+def f():
+    import hvplot.pandas.plots
+def f():
+    from hvplot.pandas import scatter_matrix
+def f():
+    from hvplot.pandas.plots import scatter_matrix
--- a/crates/ruff_linter/resources/test/fixtures/pyflakes/F841_0.py
+++ b/crates/ruff_linter/resources/test/fixtures/pyflakes/F841_0.py
@@ -151,3 +151,39 @@ def f():
        pass
    except Exception as _:
        pass
+
+
+# OK, `__class__` in this case is not the special `__class__` cell, so we don't
+# emit a diagnostic. (It has its own special semantics -- see
+# https://github.com/astral-sh/ruff/pull/20048#discussion_r2298338048 -- but
+# those aren't relevant here.)
+class A:
+    __class__ = 1
+
+
+# The following three cases are flagged because they declare local `__class__`
+# variables that don't refer to the special `__class__` cell.
+class A:
+    def set_class(self, cls):
+        __class__ = cls  # F841
+
+
+class A:
+    class B:
+        def set_class(self, cls):
+            __class__ = cls  # F841
+
+
+class A:
+    def foo():
+        class B:
+            print(__class__)
+            def set_class(self, cls):
+                __class__ = cls  # F841
+
+
+# OK, the `__class__` cell is nonlocal and declared as such.
+class NonlocalDunderClass:
+    def foo():
+        nonlocal __class__
+        __class__ = 1
--- a/crates/ruff_linter/resources/test/fixtures/pylint/nonlocal_without_binding.py
+++ b/crates/ruff_linter/resources/test/fixtures/pylint/nonlocal_without_binding.py
@@ -44,3 +44,8 @@ def f():
    def g():
        nonlocal x
        x = 2
+
+# OK
+class A:
+    def method(self):
+        nonlocal __class__
--- a/crates/ruff_linter/resources/test/fixtures/pyupgrade/UP010_0.py
+++ b/crates/ruff_linter/resources/test/fixtures/pyupgrade/UP010_0.py
--- a/crates/ruff_linter/resources/test/fixtures/pyupgrade/UP010_1.py
+++ b/crates/ruff_linter/resources/test/fixtures/pyupgrade/UP010_1.py
@@ -0,0 +1,18 @@
+from __future__ import nested_scopes, generators
+from __future__ import with_statement, unicode_literals
+
+from __future__ import absolute_import, division
+from __future__ import generator_stop
+from __future__ import print_function, nested_scopes, generator_stop
+
+print(with_statement)
+generators = 1
+
+
+class Foo():
+
+    def boo(self):
+        print(division)
+
+
+__all__ = ["print_function", "generator_stop"]
--- a/crates/ruff_linter/resources/test/fixtures/pyupgrade/UP045.py
+++ b/crates/ruff_linter/resources/test/fixtures/pyupgrade/UP045.py
@@ -69,3 +69,10 @@ a7: OptionalTE[typing.NamedTuple] = None
 a8: typing_extensions.Optional[typing.NamedTuple] = None
 a9: "Optional[NamedTuple]" = None
 a10: Optional[NamedTupleTE] = None
+
+
+# Test for: https://github.com/astral-sh/ruff/issues/19746
+# Nested Optional types should be flattened
+nested_optional: Optional[Optional[str]] = None
+nested_optional_typing: typing.Optional[Optional[int]] = None
+triple_nested_optional: Optional[Optional[Optional[str]]] = None
--- a/crates/ruff_linter/resources/test/fixtures/ruff/RUF026.py
+++ b/crates/ruff_linter/resources/test/fixtures/ruff/RUF026.py
@@ -118,3 +118,10 @@ def func():
        return lambda: value

    defaultdict(constant_factory("<missing>"))
+
+def func():
+    defaultdict(default_factory=t"")  # OK
+
+
+def func():
+    defaultdict(default_factory=t"hello")  # OK
--- a/crates/ruff_linter/resources/test/fixtures/ruff/RUF033.py
+++ b/crates/ruff_linter/resources/test/fixtures/ruff/RUF033.py
@@ -124,3 +124,19 @@ def fun_with_python_syntax():
            ...

    return Foo
+
+
+@dataclass
+class C:
+    def __post_init__(self, x: tuple[int, ...] = (
+        1,
+        2,
+    )) -> None:
+        self.x = x
+
+
+@dataclass
+class D:
+    def __post_init__(self, x: int = """
+    """) -> None:
+        self.x = x
--- a/crates/ruff_linter/resources/test/fixtures/ruff/RUF037.py
+++ b/crates/ruff_linter/resources/test/fixtures/ruff/RUF037.py
@@ -102,3 +102,8 @@ deque("abc") # OK
 deque(b"abc") # OK
 deque(f"" "a")  # OK
 deque(f"{x}" "")  # OK
+
+# https://github.com/astral-sh/ruff/issues/19951
+deque(t"")
+deque(t""  t"")
+deque(t"{""}") # OK
--- a/crates/ruff_linter/resources/test/fixtures/ruff/RUF064.py
+++ b/crates/ruff_linter/resources/test/fixtures/ruff/RUF064.py
@@ -51,3 +51,11 @@ dbm.ndbm.open("db", "r", 0o600)  # OK

 os.fchmod(0, 256)  # 0o400
 os.fchmod(0, 493)  # 0o755
+
+# https://github.com/astral-sh/ruff/issues/19010
+os.chmod("foo", 000)  # Error
+os.chmod("foo", 0000)  # Error
+
+os.chmod("foo", 0b0)  # Error
+os.chmod("foo", 0x0)  # Error
+os.chmod("foo", 0)  # Ok
--- a/crates/ruff_linter/src/checkers/ast/analyze/deferred_scopes.rs
+++ b/crates/ruff_linter/src/checkers/ast/analyze/deferred_scopes.rs
@@ -1,10 +1,11 @@
+use ruff_python_ast::PythonVersion;
 use ruff_python_semantic::{Binding, ScopeKind};

 use crate::checkers::ast::Checker;
 use crate::codes::Rule;
 use crate::rules::{
    flake8_builtins, flake8_pyi, flake8_type_checking, flake8_unused_arguments, pep8_naming,
-    pyflakes, pylint, ruff,
+    pyflakes, pylint, pyupgrade, ruff,
 };

 /// Run lint rules over all deferred scopes in the [`SemanticModel`].
@@ -45,6 +46,7 @@ pub(crate) fn deferred_scopes(checker: &Checker) {
        Rule::UnusedStaticMethodArgument,
        Rule::UnusedUnpackedVariable,
        Rule::UnusedVariable,
+        Rule::UnnecessaryFutureImport,
    ]) {
        return;
    }
@@ -224,6 +226,11 @@ pub(crate) fn deferred_scopes(checker: &Checker) {
            if checker.is_rule_enabled(Rule::UnusedImport) {
                pyflakes::rules::unused_import(checker, scope);
            }
+            if checker.is_rule_enabled(Rule::UnnecessaryFutureImport) {
+                if checker.target_version() >= PythonVersion::PY37 {
+                    pyupgrade::rules::unnecessary_future_import(checker, scope);
+                }
+            }

            if checker.is_rule_enabled(Rule::ImportPrivateName) {
                pylint::rules::import_private_name(checker, scope);
--- a/crates/ruff_linter/src/checkers/ast/analyze/expression.rs
+++ b/crates/ruff_linter/src/checkers/ast/analyze/expression.rs
@@ -660,6 +660,9 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
            if checker.is_rule_enabled(Rule::BlockingHttpCallInAsyncFunction) {
                flake8_async::rules::blocking_http_call(checker, call);
            }
+            if checker.is_rule_enabled(Rule::BlockingHttpCallHttpxInAsyncFunction) {
+                flake8_async::rules::blocking_http_call_httpx(checker, call);
+            }
            if checker.is_rule_enabled(Rule::BlockingOpenCallInAsyncFunction) {
                flake8_async::rules::blocking_open_call(checker, call);
            }
@@ -1039,8 +1042,6 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
                flake8_simplify::rules::zip_dict_keys_and_values(checker, call);
            }
            if checker.any_rule_enabled(&[
-                Rule::OsMkdir,
-                Rule::OsMakedirs,
                Rule::OsStat,
                Rule::OsPathJoin,
                Rule::OsPathSplitext,
@@ -1048,7 +1049,6 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
                Rule::PyPath,
                Rule::Glob,
                Rule::OsListdir,
-                Rule::OsSymlink,
            ]) {
                flake8_use_pathlib::rules::replaceable_by_pathlib(checker, call);
            }
@@ -1120,6 +1120,15 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
                if checker.is_rule_enabled(Rule::OsPathSamefile) {
                    flake8_use_pathlib::rules::os_path_samefile(checker, call, segments);
                }
+                if checker.is_rule_enabled(Rule::OsMkdir) {
+                    flake8_use_pathlib::rules::os_mkdir(checker, call, segments);
+                }
+                if checker.is_rule_enabled(Rule::OsMakedirs) {
+                    flake8_use_pathlib::rules::os_makedirs(checker, call, segments);
+                }
+                if checker.is_rule_enabled(Rule::OsSymlink) {
+                    flake8_use_pathlib::rules::os_symlink(checker, call, segments);
+                }
                if checker.is_rule_enabled(Rule::PathConstructorCurrentDirectory) {
                    flake8_use_pathlib::rules::path_constructor_current_directory(
                        checker, call, segments,
--- a/crates/ruff_linter/src/checkers/ast/analyze/statement.rs
+++ b/crates/ruff_linter/src/checkers/ast/analyze/statement.rs
@@ -728,13 +728,6 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
                    pylint::rules::non_ascii_module_import(checker, alias);
                }
            }
-            if checker.is_rule_enabled(Rule::UnnecessaryFutureImport) {
-                if checker.target_version() >= PythonVersion::PY37 {
-                    if let Some("__future__") = module {
-                        pyupgrade::rules::unnecessary_future_import(checker, stmt, names);
-                    }
-                }
-            }
            if checker.is_rule_enabled(Rule::DeprecatedMockImport) {
                pyupgrade::rules::deprecated_mock_import(checker, stmt);
            }
--- a/crates/ruff_linter/src/checkers/ast/mod.rs
+++ b/crates/ruff_linter/src/checkers/ast/mod.rs
@@ -28,7 +28,7 @@ use itertools::Itertools;
 use log::debug;
 use rustc_hash::{FxHashMap, FxHashSet};

-use ruff_db::diagnostic::Diagnostic;
+use ruff_db::diagnostic::{Annotation, Diagnostic, IntoDiagnosticMessage, Span};
 use ruff_diagnostics::{Applicability, Fix, IsolationLevel};
 use ruff_notebook::{CellOffsets, NotebookIndex};
 use ruff_python_ast::helpers::{collect_import_from_member, is_docstring_stmt, to_module_path};
@@ -684,8 +684,7 @@ impl SemanticSyntaxContext for Checker<'_> {
            | SemanticSyntaxErrorKind::LoadBeforeNonlocalDeclaration { .. }
            | SemanticSyntaxErrorKind::NonlocalAndGlobal(_)
            | SemanticSyntaxErrorKind::AnnotatedGlobal(_)
-            | SemanticSyntaxErrorKind::AnnotatedNonlocal(_)
-            | SemanticSyntaxErrorKind::NoBindingForNonlocal(_) => {
+            | SemanticSyntaxErrorKind::AnnotatedNonlocal(_) => {
                self.semantic_errors.borrow_mut().push(error);
            }
        }
@@ -704,7 +703,10 @@ impl SemanticSyntaxContext for Checker<'_> {
            match scope.kind {
                ScopeKind::Class(_) | ScopeKind::Lambda(_) => return false,
                ScopeKind::Function(ast::StmtFunctionDef { is_async, .. }) => return *is_async,
-                ScopeKind::Generator { .. } | ScopeKind::Module | ScopeKind::Type => {}
+                ScopeKind::Generator { .. }
+                | ScopeKind::Module
+                | ScopeKind::Type
+                | ScopeKind::DunderClassCell => {}
            }
        }
        false
@@ -715,7 +717,10 @@ impl SemanticSyntaxContext for Checker<'_> {
            match scope.kind {
                ScopeKind::Class(_) => return false,
                ScopeKind::Function(_) | ScopeKind::Lambda(_) => return true,
-                ScopeKind::Generator { .. } | ScopeKind::Module | ScopeKind::Type => {}
+                ScopeKind::Generator { .. }
+                | ScopeKind::Module
+                | ScopeKind::Type
+                | ScopeKind::DunderClassCell => {}
            }
        }
        false
@@ -726,7 +731,7 @@ impl SemanticSyntaxContext for Checker<'_> {
            match scope.kind {
                ScopeKind::Class(_) | ScopeKind::Generator { .. } => return false,
                ScopeKind::Function(_) | ScopeKind::Lambda(_) => return true,
-                ScopeKind::Module | ScopeKind::Type => {}
+                ScopeKind::Module | ScopeKind::Type | ScopeKind::DunderClassCell => {}
            }
        }
        false
@@ -1093,6 +1098,24 @@ impl<'a> Visitor<'a> for Checker<'a> {
                    }
                }

+                // Here we add the implicit scope surrounding a method which allows code in the
+                // method to access `__class__` at runtime. See the `ScopeKind::DunderClassCell`
+                // docs for more information.
+                let added_dunder_class_scope = if self.semantic.current_scope().kind.is_class() {
+                    self.semantic.push_scope(ScopeKind::DunderClassCell);
+                    let binding_id = self.semantic.push_binding(
+                        TextRange::default(),
+                        BindingKind::DunderClassCell,
+                        BindingFlags::empty(),
+                    );
+                    self.semantic
+                        .current_scope_mut()
+                        .add("__class__", binding_id);
+                    true
+                } else {
+                    false
+                };
+
                self.semantic.push_scope(ScopeKind::Type);

                if let Some(type_params) = type_params {
@@ -1156,6 +1179,9 @@ impl<'a> Visitor<'a> for Checker<'a> {
                self.semantic.pop_scope(); // Function scope
                self.semantic.pop_definition();
                self.semantic.pop_scope(); // Type parameter scope
+                if added_dunder_class_scope {
+                    self.semantic.pop_scope(); // `__class__` cell closure scope
+                }
                self.add_binding(
                    name,
                    stmt.identifier(),
@@ -3306,6 +3332,17 @@ impl DiagnosticGuard<'_, '_> {
            Err(err) => log::debug!("Failed to create fix for {}: {}", self.name(), err),
        }
    }
+
+    /// Add a secondary annotation with the given message and range.
+    pub(crate) fn secondary_annotation<'a>(
+        &mut self,
+        message: impl IntoDiagnosticMessage + 'a,
+        range: impl Ranged,
+    ) {
+        let span = Span::from(self.context.source_file.clone()).with_range(range.range());
+        let ann = Annotation::secondary(span).message(message);
+        self.diagnostic.as_mut().unwrap().annotate(ann);
+    }
 }

 impl std::ops::Deref for DiagnosticGuard<'_, '_> {
--- a/crates/ruff_linter/src/codes.rs
+++ b/crates/ruff_linter/src/codes.rs
@@ -336,6 +336,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
        (Flake8Async, "115") => (RuleGroup::Stable, rules::flake8_async::rules::AsyncZeroSleep),
        (Flake8Async, "116") => (RuleGroup::Preview, rules::flake8_async::rules::LongSleepNotForever),
        (Flake8Async, "210") => (RuleGroup::Stable, rules::flake8_async::rules::BlockingHttpCallInAsyncFunction),
+        (Flake8Async, "212") => (RuleGroup::Preview, rules::flake8_async::rules::BlockingHttpCallHttpxInAsyncFunction),
        (Flake8Async, "220") => (RuleGroup::Stable, rules::flake8_async::rules::CreateSubprocessInAsyncFunction),
        (Flake8Async, "221") => (RuleGroup::Stable, rules::flake8_async::rules::RunProcessInAsyncFunction),
        (Flake8Async, "222") => (RuleGroup::Stable, rules::flake8_async::rules::WaitForProcessInAsyncFunction),
@@ -921,8 +922,8 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
        // flake8-use-pathlib
        (Flake8UsePathlib, "100") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathAbspath),
        (Flake8UsePathlib, "101") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsChmod),
-        (Flake8UsePathlib, "102") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsMkdir),
-        (Flake8UsePathlib, "103") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsMakedirs),
+        (Flake8UsePathlib, "102") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsMkdir),
+        (Flake8UsePathlib, "103") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsMakedirs),
        (Flake8UsePathlib, "104") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsRename),
        (Flake8UsePathlib, "105") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsReplace),
        (Flake8UsePathlib, "106") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsRmdir),
@@ -954,7 +955,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
        (Flake8UsePathlib, "207") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::Glob),
        (Flake8UsePathlib, "208") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsListdir),
        (Flake8UsePathlib, "210") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::InvalidPathlibWithSuffix),
-        (Flake8UsePathlib, "211") => (RuleGroup::Preview, rules::flake8_use_pathlib::violations::OsSymlink),
+        (Flake8UsePathlib, "211") => (RuleGroup::Preview, rules::flake8_use_pathlib::rules::OsSymlink),

        // flake8-logging-format
        (Flake8LoggingFormat, "001") => (RuleGroup::Stable, rules::flake8_logging_format::violations::LoggingStringFormat),
--- a/crates/ruff_linter/src/fs.rs
+++ b/crates/ruff_linter/src/fs.rs
@@ -58,13 +58,3 @@ pub fn relativize_path<P: AsRef<Path>>(path: P) -> String {
    }
    format!("{}", path.display())
 }
-
-/// Convert an absolute path to be relative to the specified project root.
-pub fn relativize_path_to<P: AsRef<Path>, R: AsRef<Path>>(path: P, project_root: R) -> String {
-    format!(
-        "{}",
-        pathdiff::diff_paths(&path, project_root)
-            .expect("Could not diff paths")
-            .display()
-    )
-}
--- a/crates/ruff_linter/src/importer/insertion.rs
+++ b/crates/ruff_linter/src/importer/insertion.rs
@@ -63,9 +63,9 @@ impl<'a> Insertion<'a> {
                return Insertion::inline(" ", location.add(offset).add(TextSize::of(';')), ";");
            }

-            // If the first token after the docstring is a continuation character (i.e. "\"), advance
-            // an additional row to prevent inserting in the same logical line.
-            if match_continuation(locator.after(location)).is_some() {
+            // While the first token after the docstring is a continuation character (i.e. "\"), advance
+            // additional rows to prevent inserting in the same logical line.
+            while match_continuation(locator.after(location)).is_some() {
                location = locator.full_line_end(location);
            }

@@ -379,6 +379,17 @@ mod tests {
            Insertion::own_line("", TextSize::from(22), "\n")
        );

+        let contents = r#"
+"""Hello, world!"""\
+\
+
+"#
+        .trim_start();
+        assert_eq!(
+            insert(contents)?,
+            Insertion::own_line("", TextSize::from(24), "\n")
+        );
+
        let contents = r"
 x = 1
 "
--- a/crates/ruff_linter/src/linter.rs
+++ b/crates/ruff_linter/src/linter.rs
@@ -44,44 +44,15 @@ pub struct LinterResult {
    /// Flag indicating that the parsed source code does not contain any
    /// [`ParseError`]s
    has_valid_syntax: bool,
-    /// Flag indicating that the parsed source code does not contain any [`ParseError`]s,
-    /// [`UnsupportedSyntaxError`]s, or [`SemanticSyntaxError`]s.
-    has_no_syntax_errors: bool,
 }

 impl LinterResult {
-    /// Returns `true` if the parsed source code contains any [`ParseError`]s *or*
-    /// [`UnsupportedSyntaxError`]s.
-    ///
-    /// See [`LinterResult::has_invalid_syntax`] for a version specific to [`ParseError`]s.
-    pub fn has_syntax_errors(&self) -> bool {
-        !self.has_no_syntax_errors()
-    }
-
-    /// Returns `true` if the parsed source code does not contain any [`ParseError`]s *or*
-    /// [`UnsupportedSyntaxError`]s.
-    ///
-    /// See [`LinterResult::has_valid_syntax`] for a version specific to [`ParseError`]s.
-    pub fn has_no_syntax_errors(&self) -> bool {
-        self.has_valid_syntax() && self.has_no_syntax_errors
-    }
-
-    /// Returns `true` if the parsed source code is valid i.e., it has no [`ParseError`]s.
-    ///
-    /// Note that this does not include version-related [`UnsupportedSyntaxError`]s.
-    ///
-    /// See [`LinterResult::has_no_syntax_errors`] for a version that takes these into account.
-    pub fn has_valid_syntax(&self) -> bool {
-        self.has_valid_syntax
-    }
-
    /// Returns `true` if the parsed source code is invalid i.e., it has [`ParseError`]s.
    ///
-    /// Note that this does not include version-related [`UnsupportedSyntaxError`]s.
-    ///
-    /// See [`LinterResult::has_no_syntax_errors`] for a version that takes these into account.
+    /// Note that this does not include version-related [`UnsupportedSyntaxError`]s or
+    /// [`SemanticSyntaxError`]s.
    pub fn has_invalid_syntax(&self) -> bool {
-        !self.has_valid_syntax()
+        !self.has_valid_syntax
    }
 }

@@ -513,7 +484,6 @@ pub fn lint_only(

    LinterResult {
        has_valid_syntax: parsed.has_valid_syntax(),
-        has_no_syntax_errors: !diagnostics.iter().any(Diagnostic::is_invalid_syntax),
        diagnostics,
    }
 }
@@ -670,7 +640,6 @@ pub fn lint_fix<'a>(
            result: LinterResult {
                diagnostics,
                has_valid_syntax,
-                has_no_syntax_errors,
            },
            transformed,
            fixed,
--- a/crates/ruff_linter/src/message/diff.rs
+++ b/crates/ruff_linter/src/message/diff.rs
@@ -1,202 +0,0 @@
-use std::fmt::{Display, Formatter};
-use std::num::NonZeroUsize;
-
-use colored::{Color, ColoredString, Colorize, Styles};
-use similar::{ChangeTag, TextDiff};
-
-use ruff_db::diagnostic::Diagnostic;
-use ruff_source_file::{OneIndexed, SourceFile};
-use ruff_text_size::{Ranged, TextRange, TextSize};
-
-use crate::text_helpers::ShowNonprinting;
-use crate::{Applicability, Fix};
-
-/// Renders a diff that shows the code fixes.
-///
-/// The implementation isn't fully fledged out and only used by tests. Before using in production, try
-/// * Improve layout
-/// * Replace tabs with spaces for a consistent experience across terminals
-/// * Replace zero-width whitespaces
-/// * Print a simpler diff if only a single line has changed
-/// * Compute the diff from the [`Edit`] because diff calculation is expensive.
-pub(super) struct Diff<'a> {
-    fix: &'a Fix,
-    source_code: &'a SourceFile,
-}
-
-impl<'a> Diff<'a> {
-    pub(crate) fn from_message(message: &'a Diagnostic) -> Option<Diff<'a>> {
-        message.fix().map(|fix| Diff {
-            source_code: message.expect_ruff_source_file(),
-            fix,
-        })
-    }
-}
-
-impl Display for Diff<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        // TODO(dhruvmanila): Add support for Notebook cells once it's user-facing
-        let mut output = String::with_capacity(self.source_code.source_text().len());
-        let mut last_end = TextSize::default();
-
-        for edit in self.fix.edits() {
-            output.push_str(
-                self.source_code
-                    .slice(TextRange::new(last_end, edit.start())),
-            );
-            output.push_str(edit.content().unwrap_or_default());
-            last_end = edit.end();
-        }
-
-        output.push_str(&self.source_code.source_text()[usize::from(last_end)..]);
-
-        let diff = TextDiff::from_lines(self.source_code.source_text(), &output);
-
-        let message = match self.fix.applicability() {
-            // TODO(zanieb): Adjust this messaging once it's user-facing
-            Applicability::Safe => "Safe fix",
-            Applicability::Unsafe => "Unsafe fix",
-            Applicability::DisplayOnly => "Display-only fix",
-        };
-        writeln!(f, "ℹ {}", message.blue())?;
-
-        let (largest_old, largest_new) = diff
-            .ops()
-            .last()
-            .map(|op| (op.old_range().start, op.new_range().start))
-            .unwrap_or_default();
-
-        let digit_with =
-            calculate_print_width(OneIndexed::from_zero_indexed(largest_new.max(largest_old)));
-
-        for (idx, group) in diff.grouped_ops(3).iter().enumerate() {
-            if idx > 0 {
-                writeln!(f, "{:-^1$}", "-", 80)?;
-            }
-            for op in group {
-                for change in diff.iter_inline_changes(op) {
-                    let sign = match change.tag() {
-                        ChangeTag::Delete => "-",
-                        ChangeTag::Insert => "+",
-                        ChangeTag::Equal => " ",
-                    };
-
-                    let line_style = LineStyle::from(change.tag());
-
-                    let old_index = change.old_index().map(OneIndexed::from_zero_indexed);
-                    let new_index = change.new_index().map(OneIndexed::from_zero_indexed);
-
-                    write!(
-                        f,
-                        "{} {} |{}",
-                        Line {
-                            index: old_index,
-                            width: digit_with
-                        },
-                        Line {
-                            index: new_index,
-                            width: digit_with
-                        },
-                        line_style.apply_to(sign).bold()
-                    )?;
-
-                    for (emphasized, value) in change.iter_strings_lossy() {
-                        let value = value.show_nonprinting();
-                        if emphasized {
-                            write!(f, "{}", line_style.apply_to(&value).underline().on_black())?;
-                        } else {
-                            write!(f, "{}", line_style.apply_to(&value))?;
-                        }
-                    }
-                    if change.missing_newline() {
-                        writeln!(f)?;
-                    }
-                }
-            }
-        }
-
-        Ok(())
-    }
-}
-
-struct LineStyle {
-    fgcolor: Option<Color>,
-    style: Option<Styles>,
-}
-
-impl LineStyle {
-    fn apply_to(&self, input: &str) -> ColoredString {
-        let mut colored = ColoredString::from(input);
-        if let Some(color) = self.fgcolor {
-            colored = colored.color(color);
-        }
-
-        if let Some(style) = self.style {
-            match style {
-                Styles::Clear => colored.clear(),
-                Styles::Bold => colored.bold(),
-                Styles::Dimmed => colored.dimmed(),
-                Styles::Underline => colored.underline(),
-                Styles::Reversed => colored.reversed(),
-                Styles::Italic => colored.italic(),
-                Styles::Blink => colored.blink(),
-                Styles::Hidden => colored.hidden(),
-                Styles::Strikethrough => colored.strikethrough(),
-            }
-        } else {
-            colored
-        }
-    }
-}
-
-impl From<ChangeTag> for LineStyle {
-    fn from(value: ChangeTag) -> Self {
-        match value {
-            ChangeTag::Equal => LineStyle {
-                fgcolor: None,
-                style: Some(Styles::Dimmed),
-            },
-            ChangeTag::Delete => LineStyle {
-                fgcolor: Some(Color::Red),
-                style: None,
-            },
-            ChangeTag::Insert => LineStyle {
-                fgcolor: Some(Color::Green),
-                style: None,
-            },
-        }
-    }
-}
-
-struct Line {
-    index: Option<OneIndexed>,
-    width: NonZeroUsize,
-}
-
-impl Display for Line {
-    fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
-        match self.index {
-            None => {
-                for _ in 0..self.width.get() {
-                    f.write_str(" ")?;
-                }
-                Ok(())
-            }
-            Some(idx) => write!(f, "{:<width$}", idx, width = self.width.get()),
-        }
-    }
-}
-
-/// Calculate the length of the string representation of `value`
-pub(super) fn calculate_print_width(mut value: OneIndexed) -> NonZeroUsize {
-    const TEN: OneIndexed = OneIndexed::from_zero_indexed(9);
-
-    let mut width = OneIndexed::ONE;
-
-    while value >= TEN {
-        value = OneIndexed::new(value.get() / 10).unwrap_or(OneIndexed::MIN);
-        width = width.checked_add(1).unwrap();
-    }
-
-    width
-}
--- a/crates/ruff_linter/src/message/gitlab.rs
+++ b/crates/ruff_linter/src/message/gitlab.rs
@@ -1,180 +0,0 @@
-use std::collections::HashSet;
-use std::collections::hash_map::DefaultHasher;
-use std::hash::{Hash, Hasher};
-use std::io::Write;
-
-use serde::ser::SerializeSeq;
-use serde::{Serialize, Serializer};
-use serde_json::json;
-
-use ruff_db::diagnostic::Diagnostic;
-
-use crate::fs::{relativize_path, relativize_path_to};
-use crate::message::{Emitter, EmitterContext};
-
-/// Generate JSON with violations in GitLab CI format
-//  https://docs.gitlab.com/ee/ci/testing/code_quality.html#implement-a-custom-tool
-pub struct GitlabEmitter {
-    project_dir: Option<String>,
-}
-
-impl Default for GitlabEmitter {
-    fn default() -> Self {
-        Self {
-            project_dir: std::env::var("CI_PROJECT_DIR").ok(),
-        }
-    }
-}
-
-impl Emitter for GitlabEmitter {
-    fn emit(
-        &mut self,
-        writer: &mut dyn Write,
-        diagnostics: &[Diagnostic],
-        context: &EmitterContext,
-    ) -> anyhow::Result<()> {
-        serde_json::to_writer_pretty(
-            writer,
-            &SerializedMessages {
-                diagnostics,
-                context,
-                project_dir: self.project_dir.as_deref(),
-            },
-        )?;
-
-        Ok(())
-    }
-}
-
-struct SerializedMessages<'a> {
-    diagnostics: &'a [Diagnostic],
-    context: &'a EmitterContext<'a>,
-    project_dir: Option<&'a str>,
-}
-
-impl Serialize for SerializedMessages<'_> {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        let mut s = serializer.serialize_seq(Some(self.diagnostics.len()))?;
-        let mut fingerprints = HashSet::<u64>::with_capacity(self.diagnostics.len());
-
-        for diagnostic in self.diagnostics {
-            let filename = diagnostic.expect_ruff_filename();
-
-            let (start_location, end_location) = if self.context.is_notebook(&filename) {
-                // We can't give a reasonable location for the structured formats,
-                // so we show one that's clearly a fallback
-                Default::default()
-            } else {
-                (
-                    diagnostic.expect_ruff_start_location(),
-                    diagnostic.expect_ruff_end_location(),
-                )
-            };
-
-            let path = self.project_dir.as_ref().map_or_else(
-                || relativize_path(&filename),
-                |project_dir| relativize_path_to(&filename, project_dir),
-            );
-
-            let mut message_fingerprint = fingerprint(diagnostic, &path, 0);
-
-            // Make sure that we do not get a fingerprint that is already in use
-            // by adding in the previously generated one.
-            while fingerprints.contains(&message_fingerprint) {
-                message_fingerprint = fingerprint(diagnostic, &path, message_fingerprint);
-            }
-            fingerprints.insert(message_fingerprint);
-
-            let (description, check_name) = if let Some(code) = diagnostic.secondary_code() {
-                (diagnostic.body().to_string(), code.as_str())
-            } else {
-                let description = diagnostic.body();
-                let description_without_prefix = description
-                    .strip_prefix("SyntaxError: ")
-                    .unwrap_or(description);
-
-                (description_without_prefix.to_string(), "syntax-error")
-            };
-
-            let value = json!({
-                "check_name": check_name,
-                "description": description,
-                "severity": "major",
-                "fingerprint": format!("{:x}", message_fingerprint),
-                "location": {
-                    "path": path,
-                    "positions": {
-                        "begin": start_location,
-                        "end": end_location,
-                    },
-                },
-            });
-
-            s.serialize_element(&value)?;
-        }
-
-        s.end()
-    }
-}
-
-/// Generate a unique fingerprint to identify a violation.
-fn fingerprint(message: &Diagnostic, project_path: &str, salt: u64) -> u64 {
-    let mut hasher = DefaultHasher::new();
-
-    salt.hash(&mut hasher);
-    message.name().hash(&mut hasher);
-    project_path.hash(&mut hasher);
-
-    hasher.finish()
-}
-
-#[cfg(test)]
-mod tests {
-    use insta::assert_snapshot;
-
-    use crate::message::GitlabEmitter;
-    use crate::message::tests::{
-        capture_emitter_output, create_diagnostics, create_syntax_error_diagnostics,
-    };
-
-    #[test]
-    fn output() {
-        let mut emitter = GitlabEmitter::default();
-        let content = capture_emitter_output(&mut emitter, &create_diagnostics());
-
-        assert_snapshot!(redact_fingerprint(&content));
-    }
-
-    #[test]
-    fn syntax_errors() {
-        let mut emitter = GitlabEmitter::default();
-        let content = capture_emitter_output(&mut emitter, &create_syntax_error_diagnostics());
-
-        assert_snapshot!(redact_fingerprint(&content));
-    }
-
-    // Redact the fingerprint because the default hasher isn't stable across platforms.
-    fn redact_fingerprint(content: &str) -> String {
-        static FINGERPRINT_HAY_KEY: &str = r#""fingerprint": ""#;
-
-        let mut output = String::with_capacity(content.len());
-        let mut last = 0;
-
-        for (start, _) in content.match_indices(FINGERPRINT_HAY_KEY) {
-            let fingerprint_hash_start = start + FINGERPRINT_HAY_KEY.len();
-            output.push_str(&content[last..fingerprint_hash_start]);
-            output.push_str("<redacted>");
-            last = fingerprint_hash_start
-                + content[fingerprint_hash_start..]
-                    .find('"')
-                    .expect("Expected terminating quote");
-        }
-
-        output.push_str(&content[last..]);
-
-        output
-    }
-}
--- a/crates/ruff_linter/src/message/grouped.rs
+++ b/crates/ruff_linter/src/message/grouped.rs
@@ -1,3 +1,4 @@
+use std::collections::BTreeMap;
 use std::fmt::{Display, Formatter};
 use std::io::Write;
 use std::num::NonZeroUsize;
@@ -6,18 +7,15 @@ use colored::Colorize;

 use ruff_db::diagnostic::Diagnostic;
 use ruff_notebook::NotebookIndex;
-use ruff_source_file::OneIndexed;
+use ruff_source_file::{LineColumn, OneIndexed};

 use crate::fs::relativize_path;
-use crate::message::diff::calculate_print_width;
-use crate::message::text::{MessageCodeFrame, RuleCodeAndBody};
-use crate::message::{Emitter, EmitterContext, MessageWithLocation, group_diagnostics_by_filename};
+use crate::message::{Emitter, EmitterContext};
 use crate::settings::types::UnsafeFixes;

 #[derive(Default)]
 pub struct GroupedEmitter {
    show_fix_status: bool,
-    show_source: bool,
    unsafe_fixes: UnsafeFixes,
 }

@@ -28,12 +26,6 @@ impl GroupedEmitter {
        self
    }

-    #[must_use]
-    pub fn with_show_source(mut self, show_source: bool) -> Self {
-        self.show_source = show_source;
-        self
-    }
-
    #[must_use]
    pub fn with_unsafe_fixes(mut self, unsafe_fixes: UnsafeFixes) -> Self {
        self.unsafe_fixes = unsafe_fixes;
@@ -60,8 +52,8 @@ impl Emitter for GroupedEmitter {
                max_column_length = max_column_length.max(message.start_location.column);
            }

-            let row_length = calculate_print_width(max_row_length);
-            let column_length = calculate_print_width(max_column_length);
+            let row_length = max_row_length.digits();
+            let column_length = max_column_length.digits();

            // Print the filename.
            writeln!(writer, "{}:", relativize_path(&*filename).underline())?;
@@ -76,29 +68,53 @@ impl Emitter for GroupedEmitter {
                        message,
                        show_fix_status: self.show_fix_status,
                        unsafe_fixes: self.unsafe_fixes,
-                        show_source: self.show_source,
                        row_length,
                        column_length,
                    }
                )?;
            }

-            // Print a blank line between files, unless we're showing the source, in which case
-            // we'll have already printed a blank line between messages.
-            if !self.show_source {
-                writeln!(writer)?;
-            }
+            // Print a blank line between files.
+            writeln!(writer)?;
        }

        Ok(())
    }
 }

+struct MessageWithLocation<'a> {
+    message: &'a Diagnostic,
+    start_location: LineColumn,
+}
+
+impl std::ops::Deref for MessageWithLocation<'_> {
+    type Target = Diagnostic;
+
+    fn deref(&self) -> &Self::Target {
+        self.message
+    }
+}
+
+fn group_diagnostics_by_filename(
+    diagnostics: &[Diagnostic],
+) -> BTreeMap<String, Vec<MessageWithLocation<'_>>> {
+    let mut grouped_messages = BTreeMap::default();
+    for diagnostic in diagnostics {
+        grouped_messages
+            .entry(diagnostic.expect_ruff_filename())
+            .or_insert_with(Vec::new)
+            .push(MessageWithLocation {
+                message: diagnostic,
+                start_location: diagnostic.expect_ruff_start_location(),
+            });
+    }
+    grouped_messages
+}
+
 struct DisplayGroupedMessage<'a> {
    message: MessageWithLocation<'a>,
    show_fix_status: bool,
    unsafe_fixes: UnsafeFixes,
-    show_source: bool,
    row_length: NonZeroUsize,
    column_length: NonZeroUsize,
    notebook_index: Option<&'a NotebookIndex>,
@@ -114,8 +130,7 @@ impl Display for DisplayGroupedMessage<'_> {
        write!(
            f,
            "  {row_padding}",
-            row_padding = " "
-                .repeat(self.row_length.get() - calculate_print_width(start_location.line).get())
+            row_padding = " ".repeat(self.row_length.get() - start_location.line.digits().get())
        )?;

        // Check if we're working on a jupyter notebook and translate positions with cell accordingly
@@ -142,9 +157,8 @@ impl Display for DisplayGroupedMessage<'_> {
            f,
            "{row}{sep}{col}{col_padding} {code_and_body}",
            sep = ":".cyan(),
-            col_padding = " ".repeat(
-                self.column_length.get() - calculate_print_width(start_location.column).get()
-            ),
+            col_padding =
+                " ".repeat(self.column_length.get() - start_location.column.digits().get()),
            code_and_body = RuleCodeAndBody {
                message,
                show_fix_status: self.show_fix_status,
@@ -152,51 +166,50 @@ impl Display for DisplayGroupedMessage<'_> {
            },
        )?;

-        if self.show_source {
-            use std::fmt::Write;
-            let mut padded = PadAdapter::new(f);
-            writeln!(
-                padded,
-                "{}",
-                MessageCodeFrame {
-                    message,
-                    notebook_index: self.notebook_index
+        Ok(())
+    }
+}
+
+pub(super) struct RuleCodeAndBody<'a> {
+    pub(crate) message: &'a Diagnostic,
+    pub(crate) show_fix_status: bool,
+    pub(crate) unsafe_fixes: UnsafeFixes,
+}
+
+impl Display for RuleCodeAndBody<'_> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        if self.show_fix_status {
+            if let Some(fix) = self.message.fix() {
+                // Do not display an indicator for inapplicable fixes
+                if fix.applies(self.unsafe_fixes.required_applicability()) {
+                    if let Some(code) = self.message.secondary_code() {
+                        write!(f, "{} ", code.red().bold())?;
+                    }
+                    return write!(
+                        f,
+                        "{fix}{body}",
+                        fix = format_args!("[{}] ", "*".cyan()),
+                        body = self.message.body(),
+                    );
                }
-            )?;
-        }
-
-        Ok(())
-    }
-}
-
-/// Adapter that adds a '  ' at the start of every line without the need to copy the string.
-/// Inspired by Rust's `debug_struct()` internal implementation that also uses a `PadAdapter`.
-struct PadAdapter<'buf> {
-    buf: &'buf mut (dyn std::fmt::Write + 'buf),
-    on_newline: bool,
-}
-
-impl<'buf> PadAdapter<'buf> {
-    fn new(buf: &'buf mut (dyn std::fmt::Write + 'buf)) -> Self {
-        Self {
-            buf,
-            on_newline: true,
-        }
-    }
-}
-
-impl std::fmt::Write for PadAdapter<'_> {
-    fn write_str(&mut self, s: &str) -> std::fmt::Result {
-        for s in s.split_inclusive('\n') {
-            if self.on_newline {
-                self.buf.write_str("  ")?;
            }
-
-            self.on_newline = s.ends_with('\n');
-            self.buf.write_str(s)?;
        }

-        Ok(())
+        if let Some(code) = self.message.secondary_code() {
+            write!(
+                f,
+                "{code} {body}",
+                code = code.red().bold(),
+                body = self.message.body(),
+            )
+        } else {
+            write!(
+                f,
+                "{code}: {body}",
+                code = self.message.id().as_str().red().bold(),
+                body = self.message.body(),
+            )
+        }
    }
 }

@@ -226,19 +239,9 @@ mod tests {
        assert_snapshot!(content);
    }

-    #[test]
-    fn show_source() {
-        let mut emitter = GroupedEmitter::default().with_show_source(true);
-        let content = capture_emitter_output(&mut emitter, &create_diagnostics());
-
-        assert_snapshot!(content);
-    }
-
    #[test]
    fn fix_status() {
-        let mut emitter = GroupedEmitter::default()
-            .with_show_fix_status(true)
-            .with_show_source(true);
+        let mut emitter = GroupedEmitter::default().with_show_fix_status(true);
        let content = capture_emitter_output(&mut emitter, &create_diagnostics());

        assert_snapshot!(content);
@@ -248,7 +251,6 @@ mod tests {
    fn fix_status_unsafe() {
        let mut emitter = GroupedEmitter::default()
            .with_show_fix_status(true)
-            .with_show_source(true)
            .with_unsafe_fixes(UnsafeFixes::Enabled);
        let content = capture_emitter_output(&mut emitter, &create_diagnostics());

--- a/crates/ruff_linter/src/message/mod.rs
+++ b/crates/ruff_linter/src/message/mod.rs
@@ -1,7 +1,5 @@
-use std::collections::BTreeMap;
 use std::fmt::Display;
 use std::io::Write;
-use std::ops::Deref;

 use rustc_hash::FxHashMap;

@@ -12,10 +10,9 @@ use ruff_db::diagnostic::{
 use ruff_db::files::File;

 pub use github::GithubEmitter;
-pub use gitlab::GitlabEmitter;
 pub use grouped::GroupedEmitter;
 use ruff_notebook::NotebookIndex;
-use ruff_source_file::{LineColumn, SourceFile};
+use ruff_source_file::SourceFile;
 use ruff_text_size::{Ranged, TextRange, TextSize};
 pub use sarif::SarifEmitter;
 pub use text::TextEmitter;
@@ -23,9 +20,7 @@ pub use text::TextEmitter;
 use crate::Fix;
 use crate::registry::Rule;

-mod diff;
 mod github;
-mod gitlab;
 mod grouped;
 mod sarif;
 mod text;
@@ -134,35 +129,6 @@ impl FileResolver for EmitterContext<'_> {
    }
 }

-struct MessageWithLocation<'a> {
-    message: &'a Diagnostic,
-    start_location: LineColumn,
-}
-
-impl Deref for MessageWithLocation<'_> {
-    type Target = Diagnostic;
-
-    fn deref(&self) -> &Self::Target {
-        self.message
-    }
-}
-
-fn group_diagnostics_by_filename(
-    diagnostics: &[Diagnostic],
-) -> BTreeMap<String, Vec<MessageWithLocation<'_>>> {
-    let mut grouped_messages = BTreeMap::default();
-    for diagnostic in diagnostics {
-        grouped_messages
-            .entry(diagnostic.expect_ruff_filename())
-            .or_insert_with(Vec::new)
-            .push(MessageWithLocation {
-                message: diagnostic,
-                start_location: diagnostic.expect_ruff_start_location(),
-            });
-    }
-    grouped_messages
-}
-
 /// Display format for [`Diagnostic`]s.
 ///
 /// The emitter serializes a slice of [`Diagnostic`]s and writes them to a [`Write`].
--- a/crates/ruff_linter/src/message/snapshots/ruff_lintermessagegitlabtestsoutput.snap
+++ b/crates/ruff_linter/src/message/snapshots/ruff_lintermessagegitlabtestsoutput.snap
@@ -1,63 +0,0 @@
---
-source: crates/ruff_linter/src/message/gitlab.rs
-expression: redact_fingerprint(&content)
---
-[
-  {
-    "check_name": "F401",
-    "description": "`os` imported but unused",
-    "fingerprint": "<redacted>",
-    "location": {
-      "path": "fib.py",
-      "positions": {
-        "begin": {
-          "column": 8,
-          "line": 1
-        },
-        "end": {
-          "column": 10,
-          "line": 1
-        }
-      }
-    },
-    "severity": "major"
-  },
-  {
-    "check_name": "F841",
-    "description": "Local variable `x` is assigned to but never used",
-    "fingerprint": "<redacted>",
-    "location": {
-      "path": "fib.py",
-      "positions": {
-        "begin": {
-          "column": 5,
-          "line": 6
-        },
-        "end": {
-          "column": 6,
-          "line": 6
-        }
-      }
-    },
-    "severity": "major"
-  },
-  {
-    "check_name": "F821",
-    "description": "Undefined name `a`",
-    "fingerprint": "<redacted>",
-    "location": {
-      "path": "undef.py",
-      "positions": {
-        "begin": {
-          "column": 4,
-          "line": 1
-        },
-        "end": {
-          "column": 5,
-          "line": 1
-        }
-      }
-    },
-    "severity": "major"
-  }
-]
--- a/crates/ruff_linter/src/message/snapshots/ruff_lintermessagegitlabtestssyntax_errors.snap
+++ b/crates/ruff_linter/src/message/snapshots/ruff_lintermessagegitlabtestssyntax_errors.snap
@@ -1,44 +0,0 @@
---
-source: crates/ruff_linter/src/message/gitlab.rs
-expression: redact_fingerprint(&content)
---
-[
-  {
-    "check_name": "syntax-error",
-    "description": "Expected one or more symbol names after import",
-    "fingerprint": "<redacted>",
-    "location": {
-      "path": "syntax_errors.py",
-      "positions": {
-        "begin": {
-          "column": 15,
-          "line": 1
-        },
-        "end": {
-          "column": 1,
-          "line": 2
-        }
-      }
-    },
-    "severity": "major"
-  },
-  {
-    "check_name": "syntax-error",
-    "description": "Expected ')', found newline",
-    "fingerprint": "<redacted>",
-    "location": {
-      "path": "syntax_errors.py",
-      "positions": {
-        "begin": {
-          "column": 12,
-          "line": 3
-        },
-        "end": {
-          "column": 1,
-          "line": 4
-        }
-      }
-    },
-    "severity": "major"
-  }
-]
--- a/crates/ruff_linter/src/message/snapshots/ruff_lintermessagegroupedtestsfix_status.snap
+++ b/crates/ruff_linter/src/message/snapshots/ruff_lintermessagegroupedtestsfix_status.snap
@@ -1,30 +1,10 @@
 ---
 source: crates/ruff_linter/src/message/grouped.rs
 expression: content
-snapshot_kind: text
 ---
 fib.py:
  1:8 F401 `os` imported but unused
-    |
-  1 | import os
-    |        ^^ F401
-    |
-    = help: Remove unused import: `os`
-  
  6:5 F841 Local variable `x` is assigned to but never used
-    |
-  4 | def fibonacci(n):
-  5 |     """Compute the nth number in the Fibonacci sequence."""
-  6 |     x = 1
-    |     ^ F841
-  7 |     if n == 0:
-  8 |         return 0
-    |
-    = help: Remove assignment to unused variable `x`
-  
+
 undef.py:
  1:4 F821 Undefined name `a`
-    |
-  1 | if a == 1: pass
-    |    ^ F821
-    |
--- a/crates/ruff_linter/src/message/snapshots/ruff_lintermessagegroupedtestsfix_status_unsafe.snap
+++ b/crates/ruff_linter/src/message/snapshots/ruff_lintermessagegroupedtestsfix_status_unsafe.snap
@@ -1,30 +1,10 @@
 ---
 source: crates/ruff_linter/src/message/grouped.rs
 expression: content
-snapshot_kind: text
 ---
 fib.py:
  1:8 F401 [*] `os` imported but unused
-    |
-  1 | import os
-    |        ^^ F401
-    |
-    = help: Remove unused import: `os`
-  
  6:5 F841 [*] Local variable `x` is assigned to but never used
-    |
-  4 | def fibonacci(n):
-  5 |     """Compute the nth number in the Fibonacci sequence."""
-  6 |     x = 1
-    |     ^ F841
-  7 |     if n == 0:
-  8 |         return 0
-    |
-    = help: Remove assignment to unused variable `x`
-  
+
 undef.py:
  1:4 F821 Undefined name `a`
-    |
-  1 | if a == 1: pass
-    |    ^ F821
-    |
--- a/crates/ruff_linter/src/message/snapshots/ruff_lintermessagegroupedtestsshow_source.snap
+++ b/crates/ruff_linter/src/message/snapshots/ruff_lintermessagegroupedtestsshow_source.snap
@@ -1,30 +0,0 @@
---
-source: crates/ruff_linter/src/message/grouped.rs
-expression: content
-snapshot_kind: text
---
-fib.py:
-  1:8 F401 `os` imported but unused
-    |
-  1 | import os
-    |        ^^ F401
-    |
-    = help: Remove unused import: `os`
-  
-  6:5 F841 Local variable `x` is assigned to but never used
-    |
-  4 | def fibonacci(n):
-  5 |     """Compute the nth number in the Fibonacci sequence."""
-  6 |     x = 1
-    |     ^ F841
-  7 |     if n == 0:
-  8 |         return 0
-    |
-    = help: Remove assignment to unused variable `x`
-  
-undef.py:
-  1:4 F821 Undefined name `a`
-    |
-  1 | if a == 1: pass
-    |    ^ F821
-    |
--- a/crates/ruff_linter/src/message/snapshots/ruff_lintermessagetexttestsdefault.snap
+++ b/crates/ruff_linter/src/message/snapshots/ruff_lintermessagetexttestsdefault.snap
@@ -1,28 +1,30 @@
 ---
 source: crates/ruff_linter/src/message/text.rs
 expression: content
-snapshot_kind: text
 ---
-fib.py:1:8: F401 `os` imported but unused
+F401 `os` imported but unused
+ --> fib.py:1:8
  |
 1 | import os
-  |        ^^ F401
+  |        ^^
  |
-  = help: Remove unused import: `os`
+help: Remove unused import: `os`

-fib.py:6:5: F841 Local variable `x` is assigned to but never used
+F841 Local variable `x` is assigned to but never used
+ --> fib.py:6:5
  |
 4 | def fibonacci(n):
 5 |     """Compute the nth number in the Fibonacci sequence."""
 6 |     x = 1
-  |     ^ F841
+  |     ^
 7 |     if n == 0:
 8 |         return 0
  |
-  = help: Remove assignment to unused variable `x`
+help: Remove assignment to unused variable `x`

-undef.py:1:4: F821 Undefined name `a`
+F821 Undefined name `a`
+ --> undef.py:1:4
  |
 1 | if a == 1: pass
-  |    ^ F821
+  |    ^
  |
--- a/crates/ruff_linter/src/message/snapshots/ruff_lintermessagetexttestsfix_status.snap
+++ b/crates/ruff_linter/src/message/snapshots/ruff_lintermessagetexttestsfix_status.snap
@@ -1,28 +1,30 @@
 ---
 source: crates/ruff_linter/src/message/text.rs
 expression: content
-snapshot_kind: text
 ---
-fib.py:1:8: F401 `os` imported but unused
+F401 `os` imported but unused
+ --> fib.py:1:8
  |
 1 | import os
-  |        ^^ F401
+  |        ^^
  |
-  = help: Remove unused import: `os`
+help: Remove unused import: `os`

-fib.py:6:5: F841 Local variable `x` is assigned to but never used
+F841 Local variable `x` is assigned to but never used
+ --> fib.py:6:5
  |
 4 | def fibonacci(n):
 5 |     """Compute the nth number in the Fibonacci sequence."""
 6 |     x = 1
-  |     ^ F841
+  |     ^
 7 |     if n == 0:
 8 |         return 0
  |
-  = help: Remove assignment to unused variable `x`
+help: Remove assignment to unused variable `x`

-undef.py:1:4: F821 Undefined name `a`
+F821 Undefined name `a`
+ --> undef.py:1:4
  |
 1 | if a == 1: pass
-  |    ^ F821
+  |    ^
  |
--- a/crates/ruff_linter/src/message/snapshots/ruff_lintermessagetexttestsfix_status_unsafe.snap
+++ b/crates/ruff_linter/src/message/snapshots/ruff_lintermessagetexttestsfix_status_unsafe.snap
@@ -1,28 +1,30 @@
 ---
 source: crates/ruff_linter/src/message/text.rs
 expression: content
-snapshot_kind: text
 ---
-fib.py:1:8: F401 [*] `os` imported but unused
+F401 [*] `os` imported but unused
+ --> fib.py:1:8
  |
 1 | import os
-  |        ^^ F401
+  |        ^^
  |
-  = help: Remove unused import: `os`
+help: Remove unused import: `os`

-fib.py:6:5: F841 [*] Local variable `x` is assigned to but never used
+F841 [*] Local variable `x` is assigned to but never used
+ --> fib.py:6:5
  |
 4 | def fibonacci(n):
 5 |     """Compute the nth number in the Fibonacci sequence."""
 6 |     x = 1
-  |     ^ F841
+  |     ^
 7 |     if n == 0:
 8 |         return 0
  |
-  = help: Remove assignment to unused variable `x`
+help: Remove assignment to unused variable `x`

-undef.py:1:4: F821 Undefined name `a`
+F821 Undefined name `a`
+ --> undef.py:1:4
  |
 1 | if a == 1: pass
-  |    ^ F821
+  |    ^
  |
--- a/crates/ruff_linter/src/message/snapshots/ruff_lintermessagetexttestsnotebook_output.snap
+++ b/crates/ruff_linter/src/message/snapshots/ruff_lintermessagetexttestsnotebook_output.snap
@@ -2,29 +2,32 @@
 source: crates/ruff_linter/src/message/text.rs
 expression: content
 ---
-notebook.ipynb:cell 1:2:8: F401 [*] `os` imported but unused
+F401 [*] `os` imported but unused
+ --> notebook.ipynb:cell 1:2:8
  |
 1 | # cell 1
 2 | import os
-  |        ^^ F401
+  |        ^^
  |
-  = help: Remove unused import: `os`
+help: Remove unused import: `os`

-notebook.ipynb:cell 2:2:8: F401 [*] `math` imported but unused
+F401 [*] `math` imported but unused
+ --> notebook.ipynb:cell 2:2:8
  |
 1 | # cell 2
 2 | import math
-  |        ^^^^ F401
+  |        ^^^^
 3 |
 4 | print('hello world')
  |
-  = help: Remove unused import: `math`
+help: Remove unused import: `math`

-notebook.ipynb:cell 3:4:5: F841 [*] Local variable `x` is assigned to but never used
+F841 [*] Local variable `x` is assigned to but never used
+ --> notebook.ipynb:cell 3:4:5
  |
 2 | def foo():
 3 |     print()
 4 |     x = 1
-  |     ^ F841
+  |     ^
  |
-  = help: Remove assignment to unused variable `x`
+help: Remove assignment to unused variable `x`
--- a/crates/ruff_linter/src/message/snapshots/ruff_lintermessagetexttestssyntax_errors.snap
+++ b/crates/ruff_linter/src/message/snapshots/ruff_lintermessagetexttestssyntax_errors.snap
@@ -2,16 +2,17 @@
 source: crates/ruff_linter/src/message/text.rs
 expression: content
 ---
-syntax_errors.py:1:15: invalid-syntax: Expected one or more symbol names after import
+invalid-syntax: Expected one or more symbol names after import
+ --> syntax_errors.py:1:15
  |
 1 | from os import
  |               ^
 2 |
 3 | if call(foo
-4 |     def bar():
  |

-syntax_errors.py:3:12: invalid-syntax: Expected ')', found newline
+invalid-syntax: Expected ')', found newline
+ --> syntax_errors.py:3:12
  |
 1 | from os import
 2 |
--- a/crates/ruff_linter/src/message/text.rs
+++ b/crates/ruff_linter/src/message/text.rs
@@ -1,41 +1,19 @@
-use std::borrow::Cow;
-use std::fmt::{Display, Formatter};
 use std::io::Write;

-use bitflags::bitflags;
-use colored::Colorize;
-use ruff_annotate_snippets::{Level, Renderer, Snippet};
-
 use ruff_db::diagnostic::{
-    Diagnostic, DiagnosticFormat, DisplayDiagnosticConfig, SecondaryCode, ceil_char_boundary,
+    Diagnostic, DiagnosticFormat, DisplayDiagnosticConfig, DisplayDiagnostics,
 };
-use ruff_notebook::NotebookIndex;
-use ruff_source_file::OneIndexed;
-use ruff_text_size::{TextLen, TextRange, TextSize};

-use crate::message::diff::Diff;
 use crate::message::{Emitter, EmitterContext};
 use crate::settings::types::UnsafeFixes;

-bitflags! {
-    #[derive(Default)]
-    struct EmitterFlags: u8 {
-        /// Whether to show the diff of a fix, for diagnostics that have a fix.
-        const SHOW_FIX_DIFF     = 1 << 1;
-        /// Whether to show the source code of a diagnostic.
-        const SHOW_SOURCE       = 1 << 2;
-    }
-}
-
 pub struct TextEmitter {
-    flags: EmitterFlags,
    config: DisplayDiagnosticConfig,
 }

 impl Default for TextEmitter {
    fn default() -> Self {
        Self {
-            flags: EmitterFlags::default(),
            config: DisplayDiagnosticConfig::default()
                .format(DiagnosticFormat::Concise)
                .hide_severity(true)
@@ -53,13 +31,17 @@ impl TextEmitter {

    #[must_use]
    pub fn with_show_fix_diff(mut self, show_fix_diff: bool) -> Self {
-        self.flags.set(EmitterFlags::SHOW_FIX_DIFF, show_fix_diff);
+        self.config = self.config.show_fix_diff(show_fix_diff);
        self
    }

    #[must_use]
    pub fn with_show_source(mut self, show_source: bool) -> Self {
-        self.flags.set(EmitterFlags::SHOW_SOURCE, show_source);
+        self.config = self.config.format(if show_source {
+            DiagnosticFormat::Full
+        } else {
+            DiagnosticFormat::Concise
+        });
        self
    }

@@ -91,297 +73,16 @@ impl Emitter for TextEmitter {
        diagnostics: &[Diagnostic],
        context: &EmitterContext,
    ) -> anyhow::Result<()> {
-        for message in diagnostics {
-            write!(writer, "{}", message.display(context, &self.config))?;
-
-            let filename = message.expect_ruff_filename();
-            let notebook_index = context.notebook_index(&filename);
-            if self.flags.intersects(EmitterFlags::SHOW_SOURCE) {
-                // The `0..0` range is used to highlight file-level diagnostics.
-                if message.expect_range() != TextRange::default() {
-                    writeln!(
-                        writer,
-                        "{}",
-                        MessageCodeFrame {
-                            message,
-                            notebook_index
-                        }
-                    )?;
-                }
-            }
-
-            if self.flags.intersects(EmitterFlags::SHOW_FIX_DIFF) {
-                if let Some(diff) = Diff::from_message(message) {
-                    writeln!(writer, "{diff}")?;
-                }
-            }
-        }
+        write!(
+            writer,
+            "{}",
+            DisplayDiagnostics::new(context, &self.config, diagnostics)
+        )?;

        Ok(())
    }
 }

-pub(super) struct RuleCodeAndBody<'a> {
-    pub(crate) message: &'a Diagnostic,
-    pub(crate) show_fix_status: bool,
-    pub(crate) unsafe_fixes: UnsafeFixes,
-}
-
-impl Display for RuleCodeAndBody<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        if self.show_fix_status {
-            if let Some(fix) = self.message.fix() {
-                // Do not display an indicator for inapplicable fixes
-                if fix.applies(self.unsafe_fixes.required_applicability()) {
-                    if let Some(code) = self.message.secondary_code() {
-                        write!(f, "{} ", code.red().bold())?;
-                    }
-                    return write!(
-                        f,
-                        "{fix}{body}",
-                        fix = format_args!("[{}] ", "*".cyan()),
-                        body = self.message.body(),
-                    );
-                }
-            }
-        }
-
-        if let Some(code) = self.message.secondary_code() {
-            write!(
-                f,
-                "{code} {body}",
-                code = code.red().bold(),
-                body = self.message.body(),
-            )
-        } else {
-            write!(
-                f,
-                "{code}: {body}",
-                code = self.message.id().as_str().red().bold(),
-                body = self.message.body(),
-            )
-        }
-    }
-}
-
-pub(super) struct MessageCodeFrame<'a> {
-    pub(crate) message: &'a Diagnostic,
-    pub(crate) notebook_index: Option<&'a NotebookIndex>,
-}
-
-impl Display for MessageCodeFrame<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        let suggestion = self.message.first_help_text();
-        let footers = if let Some(suggestion) = suggestion {
-            vec![Level::Help.title(suggestion)]
-        } else {
-            Vec::new()
-        };
-
-        let source_file = self.message.expect_ruff_source_file();
-        let source_code = source_file.to_source_code();
-
-        let content_start_index = source_code.line_index(self.message.expect_range().start());
-        let mut start_index = content_start_index.saturating_sub(2);
-
-        // If we're working with a Jupyter Notebook, skip the lines which are
-        // outside of the cell containing the diagnostic.
-        if let Some(index) = self.notebook_index {
-            let content_start_cell = index.cell(content_start_index).unwrap_or(OneIndexed::MIN);
-            while start_index < content_start_index {
-                if index.cell(start_index).unwrap_or(OneIndexed::MIN) == content_start_cell {
-                    break;
-                }
-                start_index = start_index.saturating_add(1);
-            }
-        }
-
-        // Trim leading empty lines.
-        while start_index < content_start_index {
-            if !source_code.line_text(start_index).trim().is_empty() {
-                break;
-            }
-            start_index = start_index.saturating_add(1);
-        }
-
-        let content_end_index = source_code.line_index(self.message.expect_range().end());
-        let mut end_index = content_end_index
-            .saturating_add(2)
-            .min(OneIndexed::from_zero_indexed(source_code.line_count()));
-
-        // If we're working with a Jupyter Notebook, skip the lines which are
-        // outside of the cell containing the diagnostic.
-        if let Some(index) = self.notebook_index {
-            let content_end_cell = index.cell(content_end_index).unwrap_or(OneIndexed::MIN);
-            while end_index > content_end_index {
-                if index.cell(end_index).unwrap_or(OneIndexed::MIN) == content_end_cell {
-                    break;
-                }
-                end_index = end_index.saturating_sub(1);
-            }
-        }
-
-        // Trim trailing empty lines.
-        while end_index > content_end_index {
-            if !source_code.line_text(end_index).trim().is_empty() {
-                break;
-            }
-
-            end_index = end_index.saturating_sub(1);
-        }
-
-        let start_offset = source_code.line_start(start_index);
-        let end_offset = source_code.line_end(end_index);
-
-        let source = replace_unprintable(
-            source_code.slice(TextRange::new(start_offset, end_offset)),
-            self.message.expect_range() - start_offset,
-        )
-        .fix_up_empty_spans_after_line_terminator();
-
-        let label = self
-            .message
-            .secondary_code()
-            .map(SecondaryCode::as_str)
-            .unwrap_or_default();
-
-        let line_start = self.notebook_index.map_or_else(
-            || start_index.get(),
-            |notebook_index| {
-                notebook_index
-                    .cell_row(start_index)
-                    .unwrap_or(OneIndexed::MIN)
-                    .get()
-            },
-        );
-
-        let span = usize::from(source.annotation_range.start())
-            ..usize::from(source.annotation_range.end());
-        let annotation = Level::Error.span(span).label(label);
-        let snippet = Snippet::source(&source.text)
-            .line_start(line_start)
-            .annotation(annotation)
-            .fold(false);
-        let message = Level::None.title("").snippet(snippet).footers(footers);
-
-        let renderer = if !cfg!(test) && colored::control::SHOULD_COLORIZE.should_colorize() {
-            Renderer::styled()
-        } else {
-            Renderer::plain()
-        }
-        .cut_indicator("…");
-        let rendered = renderer.render(message);
-        writeln!(f, "{rendered}")
-    }
-}
-
-/// Given some source code and an annotation range, this routine replaces
-///  unprintable characters with printable representations of them.
-///
-/// The source code returned has an annotation that is updated to reflect
-/// changes made to the source code (if any).
-///
-/// We don't need to normalize whitespace, such as converting tabs to spaces,
-/// because `annotate-snippets` handles that internally. Similarly, it's safe to
-/// modify the annotation ranges by inserting 3-byte Unicode replacements
-/// because `annotate-snippets` will account for their actual width when
-/// rendering and displaying the column to the user.
-fn replace_unprintable(source: &str, annotation_range: TextRange) -> SourceCode<'_> {
-    let mut result = String::new();
-    let mut last_end = 0;
-    let mut range = annotation_range;
-
-    // Updates the range given by the caller whenever a single byte (at
-    // `index` in `source`) is replaced with `len` bytes.
-    //
-    // When the index occurs before the start of the range, the range is
-    // offset by `len`. When the range occurs after or at the start but before
-    // the end, then the end of the range only is offset by `len`.
-    let mut update_range = |index, len| {
-        if index < usize::from(annotation_range.start()) {
-            range += TextSize::new(len - 1);
-        } else if index < usize::from(annotation_range.end()) {
-            range = range.add_end(TextSize::new(len - 1));
-        }
-    };
-
-    // If `c` is an unprintable character, then this returns a printable
-    // representation of it (using a fancier Unicode codepoint).
-    let unprintable_replacement = |c: char| -> Option<char> {
-        match c {
-            '\x07' => Some('␇'),
-            '\x08' => Some('␈'),
-            '\x1b' => Some('␛'),
-            '\x7f' => Some('␡'),
-            _ => None,
-        }
-    };
-
-    for (index, c) in source.char_indices() {
-        if let Some(printable) = unprintable_replacement(c) {
-            result.push_str(&source[last_end..index]);
-            result.push(printable);
-            last_end = index + 1;
-
-            let len = printable.text_len().to_u32();
-            update_range(index, len);
-        }
-    }
-
-    // No tabs or unprintable chars
-    if result.is_empty() {
-        SourceCode {
-            annotation_range,
-            text: Cow::Borrowed(source),
-        }
-    } else {
-        result.push_str(&source[last_end..]);
-        SourceCode {
-            annotation_range: range,
-            text: Cow::Owned(result),
-        }
-    }
-}
-
-struct SourceCode<'a> {
-    text: Cow<'a, str>,
-    annotation_range: TextRange,
-}
-
-impl<'a> SourceCode<'a> {
-    /// This attempts to "fix up" the span on `SourceCode` in the case where
-    /// it's an empty span immediately following a line terminator.
-    ///
-    /// At present, `annotate-snippets` (both upstream and our vendored copy)
-    /// will render annotations of such spans to point to the space immediately
-    /// following the previous line. But ideally, this should point to the space
-    /// immediately preceding the next line.
-    ///
-    /// After attempting to fix `annotate-snippets` and giving up after a couple
-    /// hours, this routine takes a different tact: it adjusts the span to be
-    /// non-empty and it will cover the first codepoint of the following line.
-    /// This forces `annotate-snippets` to point to the right place.
-    ///
-    /// See also: <https://github.com/astral-sh/ruff/issues/15509>
-    fn fix_up_empty_spans_after_line_terminator(self) -> SourceCode<'a> {
-        if !self.annotation_range.is_empty()
-            || self.annotation_range.start() == TextSize::from(0)
-            || self.annotation_range.start() >= self.text.text_len()
-        {
-            return self;
-        }
-        if self.text.as_bytes()[self.annotation_range.start().to_usize() - 1] != b'\n' {
-            return self;
-        }
-        let start = self.annotation_range.start();
-        let end = ceil_char_boundary(&self.text, start + TextSize::from(1));
-        SourceCode {
-            annotation_range: TextRange::new(start, end),
-            ..self
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
    use insta::assert_snapshot;
--- a/Show More
+++ b/Show More