Merge branch 'main' into dcreager/function-enum

* main: Update pre-commit dependencies (#17506) [red-knot] Simplify visibility constraint handling for `*`-import definitions (#17486) [red-knot] Detect (some) invalid protocols (#17488) [red-knot] Correctly identify protocol classes (#17487) Update dependency ruff to v0.11.6 (#17516) Update Rust crate shellexpand to v3.1.1 (#17512) Update Rust crate proc-macro2 to v1.0.95 (#17510) Update Rust crate rand to v0.9.1 (#17511) Update Rust crate libc to v0.2.172 (#17509) Update Rust crate jiff to v0.2.9 (#17508) Update Rust crate clap to v4.5.37 (#17507) Update astral-sh/setup-uv action to v5.4.2 (#17504) Update taiki-e/install-action digest to 09dc018 (#17503) [red-knot] infer attribute assignments bound in comprehensions (#17396) [red-knot] simplify gradually-equivalent types out of unions and intersections (#17467) [red-knot] pull primer projects to run from file (#17473)
create generic context lazily
2025-04-21 13:18:36 -04:00 · 2025-04-21 13:15:09 -04:00 · 2025-04-18 17:04:26 -04:00
1015 changed files with 75912 additions and 10663 deletions
--- a/.gitattributes
+++ b/.gitattributes
@@ -12,12 +12,6 @@ crates/ruff_python_parser/resources/invalid/re_lexing/line_continuation_windows_
 crates/ruff_python_parser/resources/invalid/re_lex_logical_token_windows_eol.py text eol=crlf
 crates/ruff_python_parser/resources/invalid/re_lex_logical_token_mac_eol.py text eol=cr

-crates/ruff_linter/resources/test/fixtures/ruff/RUF046_CR.py text eol=cr
-crates/ruff_linter/resources/test/fixtures/ruff/RUF046_LF.py text eol=lf
-
-crates/ruff_linter/resources/test/fixtures/pyupgrade/UP018_CR.py text eol=cr
-crates/ruff_linter/resources/test/fixtures/pyupgrade/UP018_LF.py text eol=lf
-
 crates/ruff_python_parser/resources/inline linguist-generated=true

 ruff.schema.json -diff linguist-generated=true text=auto eol=lf
--- a/.github/actionlint.yaml
+++ b/.github/actionlint.yaml
@@ -6,6 +6,5 @@ self-hosted-runner:
  labels:
    - depot-ubuntu-latest-8
    - depot-ubuntu-22.04-16
-    - depot-ubuntu-22.04-32
    - github-windows-2025-x86_64-8
    - github-windows-2025-x86_64-16
--- a/.github/workflows/build-docker.yml
+++ b/.github/workflows/build-docker.yml
@@ -79,7 +79,7 @@ jobs:
      # Adapted from https://docs.docker.com/build/ci/github-actions/multi-platform/
      - name: Build and push by digest
        id: build
-        uses: docker/build-push-action@14487ce63c7a62a4a324b0bfb37086795e31c6c1 # v6
+        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6
        with:
          context: .
          platforms: ${{ matrix.platform }}
@@ -231,7 +231,7 @@ jobs:
            ${{ env.TAG_PATTERNS }}

      - name: Build and push
-        uses: docker/build-push-action@14487ce63c7a62a4a324b0bfb37086795e31c6c1 # v6
+        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6
        with:
          context: .
          platforms: linux/amd64,linux/arm64
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -239,11 +239,11 @@ jobs:
      - name: "Install mold"
        uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
        with:
          tool: cargo-nextest
      - name: "Install cargo insta"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
        with:
          tool: cargo-insta
      - name: Red-knot mdtests (GitHub annotations)
@@ -293,11 +293,11 @@ jobs:
      - name: "Install mold"
        uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
        with:
          tool: cargo-nextest
      - name: "Install cargo insta"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
        with:
          tool: cargo-insta
      - name: "Run tests"
@@ -320,7 +320,7 @@ jobs:
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
        with:
          tool: cargo-nextest
      - name: "Run tests"
@@ -346,7 +346,7 @@ jobs:
      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4.3.0
        with:
          node-version: 20
          cache: "npm"
@@ -403,11 +403,11 @@ jobs:
      - name: "Install mold"
        uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
        with:
          tool: cargo-nextest
      - name: "Install cargo insta"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
        with:
          tool: cargo-insta
      - name: "Run tests"
@@ -821,7 +821,7 @@ jobs:
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4.3.0
        with:
          node-version: 22
          cache: "npm"
@@ -857,7 +857,7 @@ jobs:
        run: rustup show

      - name: "Install codspeed"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
        with:
          tool: cargo-codspeed

--- a/.github/workflows/mypy_primer.yaml
+++ b/.github/workflows/mypy_primer.yaml
@@ -21,12 +21,11 @@ env:
  CARGO_NET_RETRY: 10
  CARGO_TERM_COLOR: always
  RUSTUP_MAX_RETRIES: 10
-  RUST_BACKTRACE: 1

 jobs:
  mypy_primer:
    name: Run mypy_primer
-    runs-on: depot-ubuntu-22.04-32
+    runs-on: depot-ubuntu-22.04-16
    timeout-minutes: 20
    steps:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
@@ -46,7 +45,7 @@ jobs:

      - name: Install mypy_primer
        run: |
-          uv tool install "git+https://github.com/hauntsaninja/mypy_primer@4c22d192a456e27badf85b3ea0f830707375d2b7"
+          uv tool install "git+https://github.com/astral-sh/mypy_primer.git@add-red-knot-support-v5"

      - name: Run mypy_primer
        shell: bash
--- a/.github/workflows/publish-knot-playground.yml
+++ b/.github/workflows/publish-knot-playground.yml
@@ -35,7 +35,7 @@ jobs:
          persist-credentials: false
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4.3.0
        with:
          node-version: 22
      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
--- a/.github/workflows/publish-playground.yml
+++ b/.github/workflows/publish-playground.yml
@@ -29,7 +29,7 @@ jobs:
          persist-credentials: false
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4.3.0
        with:
          node-version: 22
          cache: "npm"
--- a/.github/workflows/publish-wasm.yml
+++ b/.github/workflows/publish-wasm.yml
@@ -45,7 +45,7 @@ jobs:
          jq '.name="@astral-sh/ruff-wasm-${{ matrix.target }}"' crates/ruff_wasm/pkg/package.json > /tmp/package.json
          mv /tmp/package.json crates/ruff_wasm/pkg
      - run: cp LICENSE crates/ruff_wasm/pkg # wasm-pack does not put the LICENSE file in the pkg
-      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4.3.0
        with:
          node-version: 20
          registry-url: "https://registry.npmjs.org"
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -40,7 +40,6 @@ permissions:
 # If there's a prerelease-style suffix to the version, then the release(s)
 # will be marked as a prerelease.
 on:
-  pull_request:
  workflow_dispatch:
    inputs:
      tag:
@@ -61,7 +60,7 @@ jobs:
    env:
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
-      - uses: actions/checkout@85e6279cec87321a52edac9c87bce653a07cf6c2
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
        with:
          persist-credentials: false
          submodules: recursive
@@ -69,9 +68,9 @@ jobs:
        # we specify bash to get pipefail; it guards against the `curl` command
        # failing. otherwise `sh` won't catch that `curl` returned non-0
        shell: bash
-        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/cargo-dist/releases/download/v0.28.4/cargo-dist-installer.sh | sh"
+        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/cargo-dist/releases/download/v0.28.4-prerelease.1/cargo-dist-installer.sh | sh"
      - name: Cache dist
-        uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
        with:
          name: cargo-dist-cache
          path: ~/.cargo/bin/dist
@@ -87,7 +86,7 @@ jobs:
          cat plan-dist-manifest.json
          echo "manifest=$(jq -c "." plan-dist-manifest.json)" >> "$GITHUB_OUTPUT"
      - name: "Upload dist-manifest.json"
-        uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
        with:
          name: artifacts-plan-dist-manifest
          path: plan-dist-manifest.json
@@ -124,19 +123,19 @@ jobs:
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      BUILD_MANIFEST_NAME: target/distrib/global-dist-manifest.json
    steps:
-      - uses: actions/checkout@85e6279cec87321a52edac9c87bce653a07cf6c2
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
        with:
          persist-credentials: false
          submodules: recursive
      - name: Install cached dist
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
        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@95815c38cf2ff2164869cbab79da8d1f422bc89e
        with:
          pattern: artifacts-*
          path: target/distrib/
@@ -154,7 +153,7 @@ jobs:

          cp dist-manifest.json "$BUILD_MANIFEST_NAME"
      - name: "Upload artifacts"
-        uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
        with:
          name: artifacts-build-global
          path: |
@@ -175,19 +174,19 @@ jobs:
    outputs:
      val: ${{ steps.host.outputs.manifest }}
    steps:
-      - uses: actions/checkout@85e6279cec87321a52edac9c87bce653a07cf6c2
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
        with:
          persist-credentials: false
          submodules: recursive
      - name: Install cached dist
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
        with:
          name: cargo-dist-cache
          path: ~/.cargo/bin/
      - run: chmod +x ~/.cargo/bin/dist
      # Fetch artifacts from scratch-storage
      - name: Fetch artifacts
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
        with:
          pattern: artifacts-*
          path: target/distrib/
@@ -201,7 +200,7 @@ jobs:
          cat dist-manifest.json
          echo "manifest=$(jq -c "." dist-manifest.json)" >> "$GITHUB_OUTPUT"
      - name: "Upload dist-manifest.json"
-        uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
        with:
          # Overwrite the previous copy
          name: artifacts-dist-manifest
@@ -251,13 +250,13 @@ jobs:
    env:
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
-      - uses: actions/checkout@85e6279cec87321a52edac9c87bce653a07cf6c2
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
        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@95815c38cf2ff2164869cbab79da8d1f422bc89e
        with:
          pattern: artifacts-*
          path: artifacts
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -79,7 +79,7 @@ repos:
        pass_filenames: false # This makes it a lot faster

  - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.11.7
+    rev: v0.11.6
    hooks:
      - id: ruff-format
      - id: ruff
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,30 +1,5 @@
 # Changelog

-## 0.11.7
-
-### Preview features
-
- \[`airflow`\] Apply auto fixes to cases where the names have changed in Airflow 3 (`AIR301`) ([#17355](https://github.com/astral-sh/ruff/pull/17355))
- \[`perflint`\] Implement fix for `manual-dict-comprehension` (`PERF403`) ([#16719](https://github.com/astral-sh/ruff/pull/16719))
- [syntax-errors] Make duplicate parameter names a semantic error ([#17131](https://github.com/astral-sh/ruff/pull/17131))
-
-### Bug fixes
-
- \[`airflow`\] Fix typos in provider package names (`AIR302`, `AIR312`) ([#17574](https://github.com/astral-sh/ruff/pull/17574))
- \[`flake8-type-checking`\] Visit keyword arguments in checks involving `typing.cast`/`typing.NewType` arguments ([#17538](https://github.com/astral-sh/ruff/pull/17538))
- \[`pyupgrade`\] Preserve parenthesis when fixing native literals containing newlines (`UP018`) ([#17220](https://github.com/astral-sh/ruff/pull/17220))
- \[`refurb`\] Mark the `FURB161` fix unsafe except for integers and booleans ([#17240](https://github.com/astral-sh/ruff/pull/17240))
-
-### Rule changes
-
- \[`perflint`\] Allow list function calls to be replaced with a comprehension (`PERF401`) ([#17519](https://github.com/astral-sh/ruff/pull/17519))
- \[`pycodestyle`\] Auto-fix redundant boolean comparison (`E712`) ([#17090](https://github.com/astral-sh/ruff/pull/17090))
- \[`pylint`\] make fix unsafe if delete comments (`PLR1730`) ([#17459](https://github.com/astral-sh/ruff/pull/17459))
-
-### Documentation
-
- Add fix safety sections to docs for several rules ([#17410](https://github.com/astral-sh/ruff/pull/17410),[#17440](https://github.com/astral-sh/ruff/pull/17440),[#17441](https://github.com/astral-sh/ruff/pull/17441),[#17443](https://github.com/astral-sh/ruff/pull/17443),[#17444](https://github.com/astral-sh/ruff/pull/17444))
-
 ## 0.11.6

 ### Preview features
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -394,7 +394,7 @@ dependencies = [
 "heck",
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -490,6 +490,20 @@ dependencies = [
 "windows-sys 0.52.0",
 ]

+[[package]]
+name = "compact_str"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b79c4069c6cad78e2e0cdfcbd26275770669fb39fd308a752dc110e83b9af32"
+dependencies = [
+ "castaway",
+ "cfg-if",
+ "itoa",
+ "rustversion",
+ "ryu",
+ "static_assertions",
+]
+
 [[package]]
 name = "compact_str"
 version = "0.9.0"
@@ -710,7 +724,7 @@ dependencies = [
 "proc-macro2",
 "quote",
 "strsim",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -721,7 +735,7 @@ checksum = "d336a2a514f6ccccaa3e09b02d41d35330c07ddf03a62165fcec10bb561c7806"
 dependencies = [
 "darling_core",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -791,7 +805,7 @@ dependencies = [
 "glob",
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -823,7 +837,7 @@ checksum = "97369cbbc041bc366949bc74d34658d6cda5621039731c6310521892a3a20ae0"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -1309,7 +1323,7 @@ checksum = "1ec89e9337638ecdc08744df490b221a7399bf8d164eb52a665454e60e075ad6"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -1474,7 +1488,7 @@ dependencies = [
 "heck",
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -1539,9 +1553,9 @@ checksum = "4a5f13b858c8d314ee3e8f639011f7ccefe71f97f96e50151fb991f267928e2c"

 [[package]]
 name = "jiff"
-version = "0.2.10"
+version = "0.2.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a064218214dc6a10fbae5ec5fa888d80c45d611aba169222fc272072bf7aef6"
+checksum = "59ec30f7142be6fe14e1b021f50b85db8df2d4324ea6e91ec3e5dcde092021d0"
 dependencies = [
 "jiff-static",
 "jiff-tzdb-platform",
@@ -1549,18 +1563,18 @@ dependencies = [
 "portable-atomic",
 "portable-atomic-util",
 "serde",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
 name = "jiff-static"
-version = "0.2.10"
+version = "0.2.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "199b7932d97e325aff3a7030e141eafe7f2c6268e1d1b24859b753a627f45254"
+checksum = "526b834d727fd59d37b076b0c3236d9adde1b1729a4361e20b2026f738cc1dbe"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -1657,7 +1671,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bfa96ed35d0dccc67cf7ba49350cb86de3dcb1d072a7ab28f99117f19d874953"
 dependencies = [
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -2166,7 +2180,7 @@ dependencies = [
 "pest_meta",
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -2235,7 +2249,7 @@ checksum = "6e918e4ff8c4549eb882f14b3a4bc8c8bc93de829416eacf579f1207a8fbf861"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -2558,7 +2572,7 @@ dependencies = [
 "anyhow",
 "bitflags 2.9.0",
 "camino",
- "compact_str",
+ "compact_str 0.9.0",
 "countme",
 "dir-test",
 "drop_bomb",
@@ -2647,7 +2661,6 @@ dependencies = [
 "tempfile",
 "thiserror 2.0.12",
 "toml",
- "tracing",
 ]

 [[package]]
@@ -2759,7 +2772,7 @@ dependencies = [

 [[package]]
 name = "ruff"
-version = "0.11.7"
+version = "0.11.6"
 dependencies = [
 "anyhow",
 "argfile",
@@ -2994,7 +3007,7 @@ dependencies = [

 [[package]]
 name = "ruff_linter"
-version = "0.11.7"
+version = "0.11.6"
 dependencies = [
 "aho-corasick",
 "anyhow",
@@ -3061,7 +3074,7 @@ dependencies = [
 "proc-macro2",
 "quote",
 "ruff_python_trivia",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -3088,7 +3101,7 @@ version = "0.0.0"
 dependencies = [
 "aho-corasick",
 "bitflags 2.9.0",
- "compact_str",
+ "compact_str 0.9.0",
 "is-macro",
 "itertools 0.14.0",
 "memchr",
@@ -3186,7 +3199,7 @@ dependencies = [
 "anyhow",
 "bitflags 2.9.0",
 "bstr",
- "compact_str",
+ "compact_str 0.9.0",
 "insta",
 "memchr",
 "ruff_annotate_snippets",
@@ -3320,7 +3333,7 @@ dependencies = [

 [[package]]
 name = "ruff_wasm"
-version = "0.11.7"
+version = "0.11.6"
 dependencies = [
 "console_error_panic_hook",
 "console_log",
@@ -3444,11 +3457,11 @@ checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"

 [[package]]
 name = "salsa"
-version = "0.20.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=c75b0161aba55965ab6ad8cc9aaee7dc177967f1#c75b0161aba55965ab6ad8cc9aaee7dc177967f1"
+version = "0.19.0"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=87bf6b6c2d5f6479741271da73bd9d30c2580c26#87bf6b6c2d5f6479741271da73bd9d30c2580c26"
 dependencies = [
 "boxcar",
- "compact_str",
+ "compact_str 0.8.1",
 "crossbeam-queue",
 "dashmap 6.1.0",
 "hashbrown 0.15.2",
@@ -3467,18 +3480,18 @@ dependencies = [

 [[package]]
 name = "salsa-macro-rules"
-version = "0.20.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=c75b0161aba55965ab6ad8cc9aaee7dc177967f1#c75b0161aba55965ab6ad8cc9aaee7dc177967f1"
+version = "0.19.0"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=87bf6b6c2d5f6479741271da73bd9d30c2580c26#87bf6b6c2d5f6479741271da73bd9d30c2580c26"

 [[package]]
 name = "salsa-macros"
-version = "0.20.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=c75b0161aba55965ab6ad8cc9aaee7dc177967f1#c75b0161aba55965ab6ad8cc9aaee7dc177967f1"
+version = "0.19.0"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=87bf6b6c2d5f6479741271da73bd9d30c2580c26#87bf6b6c2d5f6479741271da73bd9d30c2580c26"
 dependencies = [
 "heck",
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 "synstructure",
 ]

@@ -3512,7 +3525,7 @@ dependencies = [
 "proc-macro2",
 "quote",
 "serde_derive_internals",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -3561,7 +3574,7 @@ checksum = "5b0276cf7f2c73365f7157c8123c21cd9a50fbbd844757af28ca1f5925fc2a00"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -3572,7 +3585,7 @@ checksum = "18d26a20a969b9e3fdf2fc2d9f21eda6c40e2de84c9408bb5d3b05d499aae711"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -3595,7 +3608,7 @@ checksum = "175ee3e80ae9982737ca543e96133087cbd9a485eecc3bc4de9c1a37b47ea59c"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -3636,7 +3649,7 @@ dependencies = [
 "darling",
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -3767,7 +3780,7 @@ dependencies = [
 "proc-macro2",
 "quote",
 "rustversion",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -3783,9 +3796,9 @@ dependencies = [

 [[package]]
 name = "syn"
-version = "2.0.101"
+version = "2.0.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ce2b7fc941b3a24138a0a7cf8e858bfc6a992e7978a068a5c760deb0ed43caf"
+checksum = "b09a44accad81e1ba1cd74a32461ba89dee89095ba17b32f5d03683b1b1fc2a0"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -3800,7 +3813,7 @@ checksum = "c8af7666ab7b6390ab78131fb5b0fce11d6b7a6951602017c35fa82800708971"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -3871,7 +3884,7 @@ dependencies = [
 "cfg-if",
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -3882,7 +3895,7 @@ checksum = "5c89e72a01ed4c579669add59014b9a524d609c0c88c6a585ce37485879f6ffb"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 "test-case-core",
 ]

@@ -3918,7 +3931,7 @@ checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -3929,7 +3942,7 @@ checksum = "7f7cf42b4507d8ea322120659672cf1b9dbb93f8f2d4ecfd6e51350ff5b17a1d"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -4060,7 +4073,7 @@ checksum = "395ae124c09f9e6918a2310af6038fba074bcf474ac352496d5910dd59a2226d"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -4327,7 +4340,7 @@ checksum = "72dcd78c4f979627a754f5522cea6e6a25e55139056535fe6e69c506cd64a862"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -4449,7 +4462,7 @@ dependencies = [
 "log",
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 "wasm-bindgen-shared",
 ]

@@ -4484,7 +4497,7 @@ checksum = "8ae87ea40c9f689fc23f209965b6fb8a99ad69aeeb0231408be24920604395de"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 "wasm-bindgen-backend",
 "wasm-bindgen-shared",
 ]
@@ -4519,7 +4532,7 @@ checksum = "17d5042cc5fa009658f9a7333ef24291b1291a25b6382dd68862a7f3b969f69b"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -4634,7 +4647,7 @@ checksum = "2bbd5b46c938e506ecbce286b6628a02171d56153ba733b6c741fc627ec9579b"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -4645,7 +4658,7 @@ checksum = "053c4c462dc91d3b1504c6fe5a726dd15e216ba718e84a0e46a88fbe5ded3515"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -4883,7 +4896,7 @@ checksum = "2380878cad4ac9aac1e2435f3eb4020e8374b5f13c296cb75b4620ff8e229154"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 "synstructure",
 ]

@@ -4904,7 +4917,7 @@ checksum = "6352c01d0edd5db859a63e2605f4ea3183ddbd15e2c4a9e7d32184df75e4f154"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
@@ -4924,7 +4937,7 @@ checksum = "d71e5d6e06ab090c67b5e44993ec16b72dcbaabc526db883a360057678b48502"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 "synstructure",
 ]

@@ -4947,7 +4960,7 @@ checksum = "6eafa6dfb17584ea3e2bd6e76e0cc15ad7af12b09abdd1ca55961bed9b1063c6"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.101",
+ "syn 2.0.100",
 ]

 [[package]]
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -124,7 +124,7 @@ rayon = { version = "1.10.0" }
 regex = { version = "1.10.2" }
 rustc-hash = { version = "2.0.0" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "c75b0161aba55965ab6ad8cc9aaee7dc177967f1" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "87bf6b6c2d5f6479741271da73bd9d30c2580c26" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
@@ -231,10 +231,6 @@ unused_peekable = "warn"
 # Diagnostics are not actionable: Enable once https://github.com/rust-lang/rust-clippy/issues/13774 is resolved.
 large_stack_arrays = "allow"

-# Salsa generates functions with parameters for each field of a `salsa::interned` struct.
-# If we don't allow this, we get warnings for structs with too many fields.
-too_many_arguments = "allow"
-
 [profile.release]
 # Note that we set these explicitly, and these values
 # were chosen based on a trade-off between compile times
@@ -276,9 +272,7 @@ inherits = "release"
 # Config for 'dist'
 [workspace.metadata.dist]
 # The preferred dist version to use in CI (Cargo.toml SemVer syntax)
-cargo-dist-version = "0.28.4"
-# Make distability of apps opt-in instead of opt-out
-dist = false
+cargo-dist-version = "0.28.4-prerelease.1"
 # CI backends to support
 ci = "github"
 # The installers to generate for each app
@@ -312,7 +306,7 @@ auto-includes = false
 # Whether dist should create a Github Release or use an existing draft
 create-release = true
 # Which actions to run on pull requests
-pr-run-mode = "plan"
+pr-run-mode = "skip"
 # Whether CI should trigger releases with dispatches instead of tag pushes
 dispatch-releases = true
 # Which phase dist should use to create the GitHub release
@@ -340,7 +334,7 @@ install-path = ["$XDG_BIN_HOME/", "$XDG_DATA_HOME/../bin", "~/.local/bin"]
 global = "depot-ubuntu-latest-4"

 [workspace.metadata.dist.github-action-commits]
-"actions/checkout" = "85e6279cec87321a52edac9c87bce653a07cf6c2" # v4
-"actions/upload-artifact" = "6027e3dd177782cd8ab9af838c04fd81a07f1d47" # v4.6.2
-"actions/download-artifact" = "d3f86a106a0bac45b974a628896c90dbdf5c8093" # v4.3.0
+"actions/checkout" = "11bd71901bbe5b1630ceea73d27597364c9af683" # v4
+"actions/upload-artifact" = "ea165f8d65b6e75b540449e92b4886f43607fa02" # v4.6.2
+"actions/download-artifact" = "95815c38cf2ff2164869cbab79da8d1f422bc89e" # v4.2.1
 "actions/attest-build-provenance" = "c074443f1aee8d4aeeae555aebba3282517141b2" #v2.2.3
--- a/README.md
+++ b/README.md
@@ -149,8 +149,8 @@ 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/0.11.7/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.11.7/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.11.6/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.11.6/install.ps1 | iex"
 ```

 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -183,7 +183,7 @@ 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: v0.11.7
+  rev: v0.11.6
  hooks:
    # Run the linter.
    - id: ruff
--- a/crates/red_knot/docs/mypy_primer.md
+++ b/crates/red_knot/docs/mypy_primer.md
@@ -2,16 +2,16 @@

 ## Basics

-`mypy_primer` can be run using `uvx --from "…" mypy_primer`. For example, to see the help message, run:
+For now, we use our own [fork of mypy primer]. It can be run using `uvx --from "…" mypy_primer`. For example, to see the help message, run:

 ```sh
-uvx --from "git+https://github.com/hauntsaninja/mypy_primer" mypy_primer -h
+uvx --from "git+https://github.com/astral-sh/mypy_primer.git@add-red-knot-support" mypy_primer -h
 ```

 Alternatively, you can install the forked version of `mypy_primer` using:

 ```sh
-uv tool install "git+https://github.com/hauntsaninja/mypy_primer"
+uv tool install "git+https://github.com/astral-sh/mypy_primer.git@add-red-knot-support"
 ```

 and then run it using `uvx mypy_primer` or just `mypy_primer`, if your `PATH` is set up accordingly (see: [Tool executables]).
@@ -56,5 +56,6 @@ mypy_primer --repo /path/to/ruff --old origin/main --new my/local-branch …

 Note that you might need to clean up `/tmp/mypy_primer` in order for this to work correctly.

-[full list of ecosystem projects]: https://github.com/hauntsaninja/mypy_primer/blob/master/mypy_primer/projects.py
+[fork of mypy primer]: https://github.com/astral-sh/mypy_primer/tree/add-red-knot-support
+[full list of ecosystem projects]: https://github.com/astral-sh/mypy_primer/blob/add-red-knot-support/mypy_primer/projects.py
 [tool executables]: https://docs.astral.sh/uv/concepts/tools/#tool-executables
--- a/crates/red_knot/src/args.rs
+++ b/crates/red_knot/src/args.rs
@@ -105,19 +105,6 @@ pub(crate) struct CheckCommand {
    /// Watch files for changes and recheck files related to the changed files.
    #[arg(long, short = 'W')]
    pub(crate) watch: bool,
-
-    /// Respect file exclusions via `.gitignore` and other standard ignore files.
-    /// Use `--no-respect-gitignore` to disable.
-    #[arg(
-        long,
-        overrides_with("no_respect_ignore_files"),
-        help_heading = "File selection",
-        default_missing_value = "true",
-        num_args = 0..1
-    )]
-    respect_ignore_files: Option<bool>,
-    #[clap(long, overrides_with("respect_ignore_files"), hide = true)]
-    no_respect_ignore_files: bool,
 }

 impl CheckCommand {
@@ -133,13 +120,6 @@ impl CheckCommand {
            )
        };

-        // --no-respect-gitignore defaults to false and is set true by CLI flag. If passed, override config file
-        // Otherwise, only pass this through if explicitly set (don't default to anything here to
-        // make sure that doesn't take precedence over an explicitly-set config file value)
-        let respect_ignore_files = self
-            .no_respect_ignore_files
-            .then_some(false)
-            .or(self.respect_ignore_files);
        Options {
            environment: Some(EnvironmentOptions {
                python_version: self
@@ -164,7 +144,6 @@ impl CheckCommand {
                error_on_warning: self.error_on_warning,
            }),
            rules,
-            respect_ignore_files,
            ..Default::default()
        }
    }
--- a/crates/red_knot/src/main.rs
+++ b/crates/red_knot/src/main.rs
@@ -169,12 +169,8 @@ pub enum ExitStatus {
    /// Checking was successful but there were errors.
    Failure = 1,

-    /// Checking failed due to an invocation error (e.g. the current directory no longer exists, incorrect CLI arguments, ...)
+    /// Checking failed.
    Error = 2,
-
-    /// Internal Red Knot error (panic, or any other error that isn't due to the user using the
-    /// program incorrectly or transient environment errors).
-    InternalError = 101,
 }

 impl Termination for ExitStatus {
@@ -250,16 +246,11 @@ impl MainLoop {
                    // Spawn a new task that checks the project. This needs to be done in a separate thread
                    // to prevent blocking the main loop here.
                    rayon::spawn(move || {
-                        match db.check() {
-                            Ok(result) => {
-                                // Send the result back to the main loop for printing.
-                                sender
-                                    .send(MainLoopMessage::CheckCompleted { result, revision })
-                                    .unwrap();
-                            }
-                            Err(cancelled) => {
-                                tracing::debug!("Check has been cancelled: {cancelled:?}");
-                            }
+                        if let Ok(result) = db.check() {
+                            // Send the result back to the main loop for printing.
+                            sender
+                                .send(MainLoopMessage::CheckCompleted { result, revision })
+                                .unwrap();
                        }
                    });
                }
@@ -273,6 +264,12 @@ impl MainLoop {
                        .format(terminal_settings.output_format)
                        .color(colored::control::SHOULD_COLORIZE.should_colorize());

+                    let min_error_severity = if terminal_settings.error_on_warning {
+                        Severity::Warning
+                    } else {
+                        Severity::Error
+                    };
+
                    if check_revision == revision {
                        if db.project().files(db).is_empty() {
                            tracing::warn!("No python files found under the given path(s)");
@@ -287,13 +284,13 @@ impl MainLoop {
                                return Ok(ExitStatus::Success);
                            }
                        } else {
-                            let mut max_severity = Severity::Info;
+                            let mut failed = false;
                            let diagnostics_count = result.len();

                            for diagnostic in result {
                                write!(stdout, "{}", diagnostic.display(db, &display_config))?;

-                                max_severity = max_severity.max(diagnostic.severity());
+                                failed |= diagnostic.severity() >= min_error_severity;
                            }

                            writeln!(
@@ -304,17 +301,10 @@ impl MainLoop {
                            )?;

                            if self.watcher.is_none() {
-                                return Ok(match max_severity {
-                                    Severity::Info => ExitStatus::Success,
-                                    Severity::Warning => {
-                                        if terminal_settings.error_on_warning {
-                                            ExitStatus::Failure
-                                        } else {
-                                            ExitStatus::Success
-                                        }
-                                    }
-                                    Severity::Error => ExitStatus::Failure,
-                                    Severity::Fatal => ExitStatus::InternalError,
+                                return Ok(if failed {
+                                    ExitStatus::Failure
+                                } else {
+                                    ExitStatus::Success
                                });
                            }
                        }
--- a/crates/red_knot/tests/cli.rs
+++ b/crates/red_knot/tests/cli.rs
@@ -5,94 +5,6 @@ use std::path::{Path, PathBuf};
 use std::process::Command;
 use tempfile::TempDir;

-#[test]
-fn test_include_hidden_files_by_default() -> anyhow::Result<()> {
-    let case = TestCase::with_files([(".test.py", "~")])?;
-    assert_cmd_snapshot!(case.command(), @r"
-    success: false
-    exit_code: 1
-    ----- stdout -----
-    error: invalid-syntax
-     --> <temp_dir>/.test.py:1:2
-      |
-    1 | ~
-      |  ^ Expected an expression
-      |
-
-    Found 1 diagnostic
-
-    ----- stderr -----
-    ");
-    Ok(())
-}
-#[test]
-fn test_respect_ignore_files() -> anyhow::Result<()> {
-    // First test that the default option works correctly (the file is skipped)
-    let case = TestCase::with_files([(".ignore", "test.py"), ("test.py", "~")])?;
-    assert_cmd_snapshot!(case.command(), @r"
-    success: true
-    exit_code: 0
-    ----- stdout -----
-    All checks passed!
-
-    ----- stderr -----
-    WARN No python files found under the given path(s)
-    ");
-
-    // Test that we can set to false via CLI
-    assert_cmd_snapshot!(case.command().arg("--no-respect-ignore-files"), @r"
-    success: false
-    exit_code: 1
-    ----- stdout -----
-    error: invalid-syntax
-     --> <temp_dir>/test.py:1:2
-      |
-    1 | ~
-      |  ^ Expected an expression
-      |
-
-    Found 1 diagnostic
-
-    ----- stderr -----
-    ");
-
-    // Test that we can set to false via config file
-    case.write_file("knot.toml", "respect-ignore-files = false")?;
-    assert_cmd_snapshot!(case.command(), @r"
-    success: false
-    exit_code: 1
-    ----- stdout -----
-    error: invalid-syntax
-     --> <temp_dir>/test.py:1:2
-      |
-    1 | ~
-      |  ^ Expected an expression
-      |
-
-    Found 1 diagnostic
-
-    ----- stderr -----
-    ");
-
-    // Ensure CLI takes precedence
-    case.write_file("knot.toml", "respect-ignore-files = true")?;
-    assert_cmd_snapshot!(case.command().arg("--no-respect-ignore-files"), @r"
-    success: false
-    exit_code: 1
-    ----- stdout -----
-    error: invalid-syntax
-     --> <temp_dir>/test.py:1:2
-      |
-    1 | ~
-      |  ^ Expected an expression
-      |
-
-    Found 1 diagnostic
-
-    ----- stderr -----
-    ");
-    Ok(())
-}
 /// Specifying an option on the CLI should take precedence over the same setting in the
 /// project's configuration. Here, this is tested for the Python version.
 #[test]
@@ -120,12 +32,12 @@ fn config_override_python_version() -> anyhow::Result<()> {
    success: false
    exit_code: 1
    ----- stdout -----
-    error: lint:unresolved-attribute: Type `<module 'sys'>` has no attribute `last_exc`
+    error: lint:unresolved-attribute
     --> <temp_dir>/test.py:5:7
      |
    4 | # Access `sys.last_exc` that was only added in Python 3.12
    5 | print(sys.last_exc)
-      |       ^^^^^^^^^^^^
+      |       ^^^^^^^^^^^^ Type `<module 'sys'>` has no attribute `last_exc`
      |

    Found 1 diagnostic
@@ -253,11 +165,11 @@ fn cli_arguments_are_relative_to_the_current_directory() -> anyhow::Result<()> {
    success: false
    exit_code: 1
    ----- stdout -----
-    error: lint:unresolved-import: Cannot resolve import `utils`
+    error: lint:unresolved-import
     --> <temp_dir>/child/test.py:2:6
      |
    2 | from utils import add
-      |      ^^^^^
+      |      ^^^^^ Cannot resolve import `utils`
    3 |
    4 | stat = add(10, 15)
      |
@@ -353,22 +265,22 @@ fn configuration_rule_severity() -> anyhow::Result<()> {
    success: false
    exit_code: 1
    ----- stdout -----
-    error: lint:division-by-zero: Cannot divide object of type `Literal[4]` by zero
+    error: lint:division-by-zero
     --> <temp_dir>/test.py:2:5
      |
    2 | y = 4 / 0
-      |     ^^^^^
+      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
    3 |
    4 | for a in range(0, int(y)):
      |

-    warning: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+    warning: lint:possibly-unresolved-reference
     --> <temp_dir>/test.py:7:7
      |
    5 |     x = a
    6 |
    7 | print(x)  # possibly-unresolved-reference
-      |       ^
+      |       ^ Name `x` used when possibly not defined
      |

    Found 2 diagnostics
@@ -389,11 +301,11 @@ fn configuration_rule_severity() -> anyhow::Result<()> {
    success: true
    exit_code: 0
    ----- stdout -----
-    warning: lint:division-by-zero: Cannot divide object of type `Literal[4]` by zero
+    warning: lint:division-by-zero
     --> <temp_dir>/test.py:2:5
      |
    2 | y = 4 / 0
-      |     ^^^^^
+      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
    3 |
    4 | for a in range(0, int(y)):
      |
@@ -429,33 +341,33 @@ fn cli_rule_severity() -> anyhow::Result<()> {
    success: false
    exit_code: 1
    ----- stdout -----
-    error: lint:unresolved-import: Cannot resolve import `does_not_exit`
+    error: lint:unresolved-import
     --> <temp_dir>/test.py:2:8
      |
    2 | import does_not_exit
-      |        ^^^^^^^^^^^^^
+      |        ^^^^^^^^^^^^^ Cannot resolve import `does_not_exit`
    3 |
    4 | y = 4 / 0
      |

-    error: lint:division-by-zero: Cannot divide object of type `Literal[4]` by zero
+    error: lint:division-by-zero
     --> <temp_dir>/test.py:4:5
      |
    2 | import does_not_exit
    3 |
    4 | y = 4 / 0
-      |     ^^^^^
+      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
    5 |
    6 | for a in range(0, int(y)):
      |

-    warning: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+    warning: lint:possibly-unresolved-reference
     --> <temp_dir>/test.py:9:7
      |
    7 |     x = a
    8 |
    9 | print(x)  # possibly-unresolved-reference
-      |       ^
+      |       ^ Name `x` used when possibly not defined
      |

    Found 3 diagnostics
@@ -476,22 +388,22 @@ fn cli_rule_severity() -> anyhow::Result<()> {
    success: true
    exit_code: 0
    ----- stdout -----
-    warning: lint:unresolved-import: Cannot resolve import `does_not_exit`
+    warning: lint:unresolved-import
     --> <temp_dir>/test.py:2:8
      |
    2 | import does_not_exit
-      |        ^^^^^^^^^^^^^
+      |        ^^^^^^^^^^^^^ Cannot resolve import `does_not_exit`
    3 |
    4 | y = 4 / 0
      |

-    warning: lint:division-by-zero: Cannot divide object of type `Literal[4]` by zero
+    warning: lint:division-by-zero
     --> <temp_dir>/test.py:4:5
      |
    2 | import does_not_exit
    3 |
    4 | y = 4 / 0
-      |     ^^^^^
+      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
    5 |
    6 | for a in range(0, int(y)):
      |
@@ -527,22 +439,22 @@ fn cli_rule_severity_precedence() -> anyhow::Result<()> {
    success: false
    exit_code: 1
    ----- stdout -----
-    error: lint:division-by-zero: Cannot divide object of type `Literal[4]` by zero
+    error: lint:division-by-zero
     --> <temp_dir>/test.py:2:5
      |
    2 | y = 4 / 0
-      |     ^^^^^
+      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
    3 |
    4 | for a in range(0, int(y)):
      |

-    warning: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+    warning: lint:possibly-unresolved-reference
     --> <temp_dir>/test.py:7:7
      |
    5 |     x = a
    6 |
    7 | print(x)  # possibly-unresolved-reference
-      |       ^
+      |       ^ Name `x` used when possibly not defined
      |

    Found 2 diagnostics
@@ -564,11 +476,11 @@ fn cli_rule_severity_precedence() -> anyhow::Result<()> {
    success: true
    exit_code: 0
    ----- stdout -----
-    warning: lint:division-by-zero: Cannot divide object of type `Literal[4]` by zero
+    warning: lint:division-by-zero
     --> <temp_dir>/test.py:2:5
      |
    2 | y = 4 / 0
-      |     ^^^^^
+      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
    3 |
    4 | for a in range(0, int(y)):
      |
@@ -643,11 +555,11 @@ fn exit_code_only_warnings() -> anyhow::Result<()> {
    success: true
    exit_code: 0
    ----- stdout -----
-    warning: lint:unresolved-reference: Name `x` used when not defined
+    warning: lint:unresolved-reference
     --> <temp_dir>/test.py:1:7
      |
    1 | print(x)  # [unresolved-reference]
-      |       ^
+      |       ^ Name `x` used when not defined
      |

    Found 1 diagnostic
@@ -726,11 +638,11 @@ fn exit_code_no_errors_but_error_on_warning_is_true() -> anyhow::Result<()> {
    success: false
    exit_code: 1
    ----- stdout -----
-    warning: lint:unresolved-reference: Name `x` used when not defined
+    warning: lint:unresolved-reference
     --> <temp_dir>/test.py:1:7
      |
    1 | print(x)  # [unresolved-reference]
-      |       ^
+      |       ^ Name `x` used when not defined
      |

    Found 1 diagnostic
@@ -758,11 +670,11 @@ fn exit_code_no_errors_but_error_on_warning_is_enabled_in_configuration() -> any
    success: false
    exit_code: 1
    ----- stdout -----
-    warning: lint:unresolved-reference: Name `x` used when not defined
+    warning: lint:unresolved-reference
     --> <temp_dir>/test.py:1:7
      |
    1 | print(x)  # [unresolved-reference]
-      |       ^
+      |       ^ Name `x` used when not defined
      |

    Found 1 diagnostic
@@ -787,20 +699,20 @@ fn exit_code_both_warnings_and_errors() -> anyhow::Result<()> {
    success: false
    exit_code: 1
    ----- stdout -----
-    warning: lint:unresolved-reference: Name `x` used when not defined
+    warning: lint:unresolved-reference
     --> <temp_dir>/test.py:2:7
      |
    2 | print(x)     # [unresolved-reference]
-      |       ^
+      |       ^ Name `x` used when not defined
    3 | print(4[1])  # [non-subscriptable]
      |

-    error: lint:non-subscriptable: Cannot subscript object of type `Literal[4]` with no `__getitem__` method
+    error: lint:non-subscriptable
     --> <temp_dir>/test.py:3:7
      |
    2 | print(x)     # [unresolved-reference]
    3 | print(4[1])  # [non-subscriptable]
-      |       ^
+      |       ^ Cannot subscript object of type `Literal[4]` with no `__getitem__` method
      |

    Found 2 diagnostics
@@ -825,20 +737,20 @@ fn exit_code_both_warnings_and_errors_and_error_on_warning_is_true() -> anyhow::
    success: false
    exit_code: 1
    ----- stdout -----
-    warning: lint:unresolved-reference: Name `x` used when not defined
+    warning: lint:unresolved-reference
     --> <temp_dir>/test.py:2:7
      |
    2 | print(x)     # [unresolved-reference]
-      |       ^
+      |       ^ Name `x` used when not defined
    3 | print(4[1])  # [non-subscriptable]
      |

-    error: lint:non-subscriptable: Cannot subscript object of type `Literal[4]` with no `__getitem__` method
+    error: lint:non-subscriptable
     --> <temp_dir>/test.py:3:7
      |
    2 | print(x)     # [unresolved-reference]
    3 | print(4[1])  # [non-subscriptable]
-      |       ^
+      |       ^ Cannot subscript object of type `Literal[4]` with no `__getitem__` method
      |

    Found 2 diagnostics
@@ -863,20 +775,20 @@ fn exit_code_exit_zero_is_true() -> anyhow::Result<()> {
    success: true
    exit_code: 0
    ----- stdout -----
-    warning: lint:unresolved-reference: Name `x` used when not defined
+    warning: lint:unresolved-reference
     --> <temp_dir>/test.py:2:7
      |
    2 | print(x)     # [unresolved-reference]
-      |       ^
+      |       ^ Name `x` used when not defined
    3 | print(4[1])  # [non-subscriptable]
      |

-    error: lint:non-subscriptable: Cannot subscript object of type `Literal[4]` with no `__getitem__` method
+    error: lint:non-subscriptable
     --> <temp_dir>/test.py:3:7
      |
    2 | print(x)     # [unresolved-reference]
    3 | print(4[1])  # [non-subscriptable]
-      |       ^
+      |       ^ Cannot subscript object of type `Literal[4]` with no `__getitem__` method
      |

    Found 2 diagnostics
@@ -923,22 +835,22 @@ fn user_configuration() -> anyhow::Result<()> {
    success: true
    exit_code: 0
    ----- stdout -----
-    warning: lint:division-by-zero: Cannot divide object of type `Literal[4]` by zero
+    warning: lint:division-by-zero
     --> <temp_dir>/project/main.py:2:5
      |
    2 | y = 4 / 0
-      |     ^^^^^
+      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
    3 |
    4 | for a in range(0, int(y)):
      |

-    warning: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+    warning: lint:possibly-unresolved-reference
     --> <temp_dir>/project/main.py:7:7
      |
    5 |     x = a
    6 |
    7 | print(x)
-      |       ^
+      |       ^ Name `x` used when possibly not defined
      |

    Found 2 diagnostics
@@ -965,22 +877,22 @@ fn user_configuration() -> anyhow::Result<()> {
    success: false
    exit_code: 1
    ----- stdout -----
-    warning: lint:division-by-zero: Cannot divide object of type `Literal[4]` by zero
+    warning: lint:division-by-zero
     --> <temp_dir>/project/main.py:2:5
      |
    2 | y = 4 / 0
-      |     ^^^^^
+      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
    3 |
    4 | for a in range(0, int(y)):
      |

-    error: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+    error: lint:possibly-unresolved-reference
     --> <temp_dir>/project/main.py:7:7
      |
    5 |     x = a
    6 |
    7 | print(x)
-      |       ^
+      |       ^ Name `x` used when possibly not defined
      |

    Found 2 diagnostics
@@ -1023,27 +935,27 @@ fn check_specific_paths() -> anyhow::Result<()> {
    success: false
    exit_code: 1
    ----- stdout -----
-    error: lint:division-by-zero: Cannot divide object of type `Literal[4]` by zero
-     --> <temp_dir>/project/main.py:2:5
-      |
-    2 | y = 4 / 0  # error: division-by-zero
-      |     ^^^^^
-      |
-
-    error: lint:unresolved-import: Cannot resolve import `main2`
-     --> <temp_dir>/project/other.py:2:6
-      |
-    2 | from main2 import z  # error: unresolved-import
-      |      ^^^^^
-    3 |
-    4 | print(z)
-      |
-
-    error: lint:unresolved-import: Cannot resolve import `does_not_exist`
+    error: lint:unresolved-import
     --> <temp_dir>/project/tests/test_main.py:2:8
      |
    2 | import does_not_exist  # error: unresolved-import
-      |        ^^^^^^^^^^^^^^
+      |        ^^^^^^^^^^^^^^ Cannot resolve import `does_not_exist`
+      |
+
+    error: lint:division-by-zero
+     --> <temp_dir>/project/main.py:2:5
+      |
+    2 | y = 4 / 0  # error: division-by-zero
+      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
+      |
+
+    error: lint:unresolved-import
+     --> <temp_dir>/project/other.py:2:6
+      |
+    2 | from main2 import z  # error: unresolved-import
+      |      ^^^^^ Cannot resolve import `main2`
+    3 |
+    4 | print(z)
      |

    Found 3 diagnostics
@@ -1060,20 +972,20 @@ fn check_specific_paths() -> anyhow::Result<()> {
    success: false
    exit_code: 1
    ----- stdout -----
-    error: lint:unresolved-import: Cannot resolve import `main2`
-     --> <temp_dir>/project/other.py:2:6
-      |
-    2 | from main2 import z  # error: unresolved-import
-      |      ^^^^^
-    3 |
-    4 | print(z)
-      |
-
-    error: lint:unresolved-import: Cannot resolve import `does_not_exist`
+    error: lint:unresolved-import
     --> <temp_dir>/project/tests/test_main.py:2:8
      |
    2 | import does_not_exist  # error: unresolved-import
-      |        ^^^^^^^^^^^^^^
+      |        ^^^^^^^^^^^^^^ Cannot resolve import `does_not_exist`
+      |
+
+    error: lint:unresolved-import
+     --> <temp_dir>/project/other.py:2:6
+      |
+    2 | from main2 import z  # error: unresolved-import
+      |      ^^^^^ Cannot resolve import `main2`
+    3 |
+    4 | print(z)
      |

    Found 2 diagnostics
--- a/crates/red_knot_project/resources/test/corpus/self_referential_function_annotation.py
+++ b/crates/red_knot_project/resources/test/corpus/self_referential_function_annotation.py
@@ -1,4 +0,0 @@
-from __future__ import annotations
-
-def foo(a: foo()):
-    pass
--- a/crates/red_knot_project/src/lib.rs
+++ b/crates/red_knot_project/src/lib.rs
@@ -11,7 +11,7 @@ use red_knot_python_semantic::register_lints;
 use red_knot_python_semantic::types::check_types;
 use ruff_db::diagnostic::{
    create_parse_diagnostic, create_unsupported_syntax_diagnostic, Annotation, Diagnostic,
-    DiagnosticId, Severity, Span, SubDiagnostic,
+    DiagnosticId, Severity, Span,
 };
 use ruff_db::files::File;
 use ruff_db::parsed::parsed_module;
@@ -20,10 +20,8 @@ use ruff_db::system::{SystemPath, SystemPathBuf};
 use rustc_hash::FxHashSet;
 use salsa::Durability;
 use salsa::Setter;
-use std::panic::{catch_unwind, AssertUnwindSafe, UnwindSafe};
 use std::sync::Arc;
 use thiserror::Error;
-use tracing::error;

 pub mod combine;

@@ -189,66 +187,30 @@ impl Project {
                .map(IOErrorDiagnostic::to_diagnostic),
        );

-        let file_diagnostics = Arc::new(std::sync::Mutex::new(vec![]));
+        let result = Arc::new(std::sync::Mutex::new(diagnostics));
+        let inner_result = Arc::clone(&result);

-        {
-            let file_diagnostics = Arc::clone(&file_diagnostics);
-            let db = db.clone();
-            let project_span = project_span.clone();
+        let db = db.clone();
+        let project_span = project_span.clone();

-            rayon::scope(move |scope| {
-                for file in &files {
-                    let result = Arc::clone(&file_diagnostics);
-                    let db = db.clone();
-                    let project_span = project_span.clone();
+        rayon::scope(move |scope| {
+            for file in &files {
+                let result = inner_result.clone();
+                let db = db.clone();
+                let project_span = project_span.clone();

-                    scope.spawn(move |_| {
-                        let check_file_span =
-                            tracing::debug_span!(parent: &project_span, "check_file", ?file);
-                        let _entered = check_file_span.entered();
+                scope.spawn(move |_| {
+                    let check_file_span =
+                        tracing::debug_span!(parent: &project_span, "check_file", ?file);
+                    let _entered = check_file_span.entered();

-                        let file_diagnostics = check_file_impl(&db, file);
-                        result.lock().unwrap().extend(file_diagnostics);
-                    });
-                }
-            });
-        }
-
-        let mut file_diagnostics = Arc::into_inner(file_diagnostics)
-            .unwrap()
-            .into_inner()
-            .unwrap();
-        // We sort diagnostics in a way that keeps them in source order
-        // and grouped by file. After that, we fall back to severity
-        // (with fatal messages sorting before info messages) and then
-        // finally the diagnostic ID.
-        file_diagnostics.sort_by(|d1, d2| {
-            if let (Some(span1), Some(span2)) = (d1.primary_span(), d2.primary_span()) {
-                let order = span1
-                    .file()
-                    .path(db)
-                    .as_str()
-                    .cmp(span2.file().path(db).as_str());
-                if order.is_ne() {
-                    return order;
-                }
-
-                if let (Some(range1), Some(range2)) = (span1.range(), span2.range()) {
-                    let order = range1.start().cmp(&range2.start());
-                    if order.is_ne() {
-                        return order;
-                    }
-                }
+                    let file_diagnostics = check_file_impl(&db, file);
+                    result.lock().unwrap().extend(file_diagnostics);
+                });
            }
-            // Reverse so that, e.g., Fatal sorts before Info.
-            let order = d1.severity().cmp(&d2.severity()).reverse();
-            if order.is_ne() {
-                return order;
-            }
-            d1.id().cmp(&d2.id())
        });
-        diagnostics.extend(file_diagnostics);
-        diagnostics
+
+        Arc::into_inner(result).unwrap().into_inner().unwrap()
    }

    pub(crate) fn check_file(self, db: &dyn Db, file: File) -> Vec<Diagnostic> {
@@ -352,23 +314,20 @@ impl Project {
    /// * It has a [`SystemPath`] and belongs to a package's `src` files
    /// * It has a [`SystemVirtualPath`](ruff_db::system::SystemVirtualPath)
    pub fn is_file_open(self, db: &dyn Db, file: File) -> bool {
-        let path = file.path(db);
-
-        // Try to return early to avoid adding a dependency on `open_files` or `file_set` which
-        // both have a durability of `LOW`.
-        if path.is_vendored_path() {
-            return false;
-        }
-
        if let Some(open_files) = self.open_files(db) {
            open_files.contains(&file)
        } else if file.path(db).is_system_path() {
-            self.files(db).contains(&file)
+            self.contains_file(db, file)
        } else {
            file.path(db).is_system_virtual_path()
        }
    }

+    /// Returns `true` if `file` is a first-party file part of this package.
+    pub fn contains_file(self, db: &dyn Db, file: File) -> bool {
+        self.files(db).contains(&file)
+    }
+
    #[tracing::instrument(level = "debug", skip(self, db))]
    pub fn remove_file(self, db: &mut dyn Db, file: File) {
        tracing::debug!(
@@ -473,16 +432,7 @@ fn check_file_impl(db: &dyn Db, file: File) -> Vec<Diagnostic> {
            .map(|error| create_unsupported_syntax_diagnostic(file, error)),
    );

-    {
-        let db = AssertUnwindSafe(db);
-        match catch(&**db, file, || check_types(db.upcast(), file)) {
-            Ok(Some(type_check_diagnostics)) => {
-                diagnostics.extend(type_check_diagnostics.into_iter().cloned());
-            }
-            Ok(None) => {}
-            Err(diagnostic) => diagnostics.push(diagnostic),
-        }
-    }
+    diagnostics.extend(check_types(db.upcast(), file).into_iter().cloned());

    diagnostics.sort_unstable_by_key(|diagnostic| {
        diagnostic
@@ -573,45 +523,6 @@ enum IOErrorKind {
    SourceText(#[from] SourceTextError),
 }

-fn catch<F, R>(db: &dyn Db, file: File, f: F) -> Result<Option<R>, Diagnostic>
-where
-    F: FnOnce() -> R + UnwindSafe,
-{
-    match catch_unwind(|| {
-        // Ignore salsa errors
-        salsa::Cancelled::catch(f).ok()
-    }) {
-        Ok(result) => Ok(result),
-        Err(error) => {
-            let payload = if let Some(s) = error.downcast_ref::<&str>() {
-                Some((*s).to_string())
-            } else {
-                error.downcast_ref::<String>().cloned()
-            };
-
-            let message = if let Some(payload) = payload {
-                format!(
-                    "Panicked while checking `{file}`: `{payload}`",
-                    file = file.path(db)
-                )
-            } else {
-                format!("Panicked while checking `{file}`", file = { file.path(db) })
-            };
-
-            let mut diagnostic = Diagnostic::new(DiagnosticId::Panic, Severity::Fatal, message);
-            diagnostic.sub(SubDiagnostic::new(
-                Severity::Info,
-                "This indicates a bug in Red Knot.",
-            ));
-
-            let report_message = "If you could open an issue at https://github.com/astral-sh/ruff/issues/new?title=%5Bred-knot%5D:%20panic we'd be very appreciative!";
-            diagnostic.sub(SubDiagnostic::new(Severity::Info, report_message));
-
-            Err(diagnostic)
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
    use crate::db::tests::TestDb;
--- a/crates/red_knot_project/src/metadata/options.rs
+++ b/crates/red_knot_project/src/metadata/options.rs
@@ -32,9 +32,6 @@ pub struct Options {

    #[serde(skip_serializing_if = "Option::is_none")]
    pub terminal: Option<TerminalOptions>,
-
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub respect_ignore_files: Option<bool>,
 }

 impl Options {
@@ -136,7 +133,7 @@ impl Options {
    pub(crate) fn to_settings(&self, db: &dyn Db) -> (Settings, Vec<OptionDiagnostic>) {
        let (rules, diagnostics) = self.to_rule_selection(db);

-        let mut settings = Settings::new(rules, self.respect_ignore_files);
+        let mut settings = Settings::new(rules);

        if let Some(terminal) = self.terminal.as_ref() {
            settings.set_terminal(TerminalSettings {
--- a/crates/red_knot_project/src/metadata/settings.rs
+++ b/crates/red_knot_project/src/metadata/settings.rs
@@ -21,16 +21,13 @@ pub struct Settings {
    rules: Arc<RuleSelection>,

    terminal: TerminalSettings,
-
-    respect_ignore_files: bool,
 }

 impl Settings {
-    pub fn new(rules: RuleSelection, respect_ignore_files: Option<bool>) -> Self {
+    pub fn new(rules: RuleSelection) -> Self {
        Self {
            rules: Arc::new(rules),
            terminal: TerminalSettings::default(),
-            respect_ignore_files: respect_ignore_files.unwrap_or(true),
        }
    }

@@ -38,10 +35,6 @@ impl Settings {
        &self.rules
    }

-    pub fn respect_ignore_files(&self) -> bool {
-        self.respect_ignore_files
-    }
-
    pub fn to_rules(&self) -> Arc<RuleSelection> {
        self.rules.clone()
    }
--- a/crates/red_knot_project/src/walk.rs
+++ b/crates/red_knot_project/src/walk.rs
@@ -129,11 +129,7 @@ impl<'a> ProjectFilesWalker<'a> {
    {
        let mut paths = paths.into_iter();

-        let mut walker = db
-            .system()
-            .walk_directory(paths.next()?.as_ref())
-            .standard_filters(db.project().settings(db).respect_ignore_files())
-            .ignore_hidden(false);
+        let mut walker = db.system().walk_directory(paths.next()?.as_ref());

        for path in paths {
            walker = walker.add(path);
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/any.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/any.md
@@ -50,9 +50,10 @@ y: Any = "not an Any"  # error: [invalid-assignment]

 The spec allows you to define subclasses of `Any`.

-`Subclass` has an unknown superclass, which might be `int`. The assignment to `x` should not be
-allowed, even when the unknown superclass is `int`. The assignment to `y` should be allowed, since
-`Subclass` might have `int` as a superclass, and is therefore assignable to `int`.
+TODO: Handle assignments correctly. `Subclass` has an unknown superclass, which might be `int`. The
+assignment to `x` should not be allowed, even when the unknown superclass is `int`. The assignment
+to `y` should be allowed, since `Subclass` might have `int` as a superclass, and is therefore
+assignable to `int`.

 ```py
 from typing import Any
@@ -62,33 +63,13 @@ class Subclass(Any): ...
 reveal_type(Subclass.__mro__)  # revealed: tuple[Literal[Subclass], Any, Literal[object]]

 x: Subclass = 1  # error: [invalid-assignment]
-y: int = Subclass()
+# TODO: no diagnostic
+y: int = Subclass()  # error: [invalid-assignment]

 def _(s: Subclass):
    reveal_type(s)  # revealed: Subclass
 ```

-`Subclass` should not be assignable to a final class though, because `Subclass` could not possibly
-be a subclass of `FinalClass`:
-
-```py
-from typing import final
-
-@final
-class FinalClass: ...
-
-f: FinalClass = Subclass()  # error: [invalid-assignment]
-```
-
-A use case where this comes up is with mocking libraries, where the mock object should be assignable
-to any type:
-
-```py
-from unittest.mock import MagicMock
-
-x: int = MagicMock()
-```
-
 ## Invalid

 `Any` cannot be parameterized:
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/invalid.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/invalid.md
@@ -56,41 +56,40 @@ def _(
 def bar() -> None:
    return None

-async def outer():  # avoid unrelated syntax errors on yield, yield from, and await
-    def _(
-        a: 1,  # error: [invalid-type-form] "Int literals are not allowed in this context in a type expression"
-        b: 2.3,  # error: [invalid-type-form] "Float literals are not allowed in type expressions"
-        c: 4j,  # error: [invalid-type-form] "Complex literals are not allowed in type expressions"
-        d: True,  # error: [invalid-type-form] "Boolean literals are not allowed in this context in a type expression"
-        e: int | b"foo",  # error: [invalid-type-form] "Bytes literals are not allowed in this context in a type expression"
-        f: 1 and 2,  # error: [invalid-type-form] "Boolean operations are not allowed in type expressions"
-        g: 1 or 2,  # error: [invalid-type-form] "Boolean operations are not allowed in type expressions"
-        h: (foo := 1),  # error: [invalid-type-form] "Named expressions are not allowed in type expressions"
-        i: not 1,  # error: [invalid-type-form] "Unary operations are not allowed in type expressions"
-        j: lambda: 1,  # error: [invalid-type-form] "`lambda` expressions are not allowed in type expressions"
-        k: 1 if True else 2,  # error: [invalid-type-form] "`if` expressions are not allowed in type expressions"
-        l: await 1,  # error: [invalid-type-form] "`await` expressions are not allowed in type expressions"
-        m: (yield 1),  # error: [invalid-type-form] "`yield` expressions are not allowed in type expressions"
-        n: (yield from [1]),  # error: [invalid-type-form] "`yield from` expressions are not allowed in type expressions"
-        o: 1 < 2,  # error: [invalid-type-form] "Comparison expressions are not allowed in type expressions"
-        p: bar(),  # error: [invalid-type-form] "Function calls are not allowed in type expressions"
-        q: int | f"foo",  # error: [invalid-type-form] "F-strings are not allowed in type expressions"
-        r: [1, 2, 3][1:2],  # error: [invalid-type-form] "Slices are not allowed in type expressions"
-    ):
-        reveal_type(a)  # revealed: Unknown
-        reveal_type(b)  # revealed: Unknown
-        reveal_type(c)  # revealed: Unknown
-        reveal_type(d)  # revealed: Unknown
-        reveal_type(e)  # revealed: int | Unknown
-        reveal_type(f)  # revealed: Unknown
-        reveal_type(g)  # revealed: Unknown
-        reveal_type(h)  # revealed: Unknown
-        reveal_type(i)  # revealed: Unknown
-        reveal_type(j)  # revealed: Unknown
-        reveal_type(k)  # revealed: Unknown
-        reveal_type(p)  # revealed: Unknown
-        reveal_type(q)  # revealed: int | Unknown
-        reveal_type(r)  # revealed: @Todo(unknown type subscript)
+def _(
+    a: 1,  # error: [invalid-type-form] "Int literals are not allowed in this context in a type expression"
+    b: 2.3,  # error: [invalid-type-form] "Float literals are not allowed in type expressions"
+    c: 4j,  # error: [invalid-type-form] "Complex literals are not allowed in type expressions"
+    d: True,  # error: [invalid-type-form] "Boolean literals are not allowed in this context in a type expression"
+    e: int | b"foo",  # error: [invalid-type-form] "Bytes literals are not allowed in this context in a type expression"
+    f: 1 and 2,  # error: [invalid-type-form] "Boolean operations are not allowed in type expressions"
+    g: 1 or 2,  # error: [invalid-type-form] "Boolean operations are not allowed in type expressions"
+    h: (foo := 1),  # error: [invalid-type-form] "Named expressions are not allowed in type expressions"
+    i: not 1,  # error: [invalid-type-form] "Unary operations are not allowed in type expressions"
+    j: lambda: 1,  # error: [invalid-type-form] "`lambda` expressions are not allowed in type expressions"
+    k: 1 if True else 2,  # error: [invalid-type-form] "`if` expressions are not allowed in type expressions"
+    l: await 1,  # error: [invalid-type-form] "`await` expressions are not allowed in type expressions"
+    m: (yield 1),  # error: [invalid-type-form] "`yield` expressions are not allowed in type expressions"
+    n: (yield from [1]),  # error: [invalid-type-form] "`yield from` expressions are not allowed in type expressions"
+    o: 1 < 2,  # error: [invalid-type-form] "Comparison expressions are not allowed in type expressions"
+    p: bar(),  # error: [invalid-type-form] "Function calls are not allowed in type expressions"
+    q: int | f"foo",  # error: [invalid-type-form] "F-strings are not allowed in type expressions"
+    r: [1, 2, 3][1:2],  # error: [invalid-type-form] "Slices are not allowed in type expressions"
+):
+    reveal_type(a)  # revealed: Unknown
+    reveal_type(b)  # revealed: Unknown
+    reveal_type(c)  # revealed: Unknown
+    reveal_type(d)  # revealed: Unknown
+    reveal_type(e)  # revealed: int | Unknown
+    reveal_type(f)  # revealed: Unknown
+    reveal_type(g)  # revealed: Unknown
+    reveal_type(h)  # revealed: Unknown
+    reveal_type(i)  # revealed: Unknown
+    reveal_type(j)  # revealed: Unknown
+    reveal_type(k)  # revealed: Unknown
+    reveal_type(p)  # revealed: Unknown
+    reveal_type(q)  # revealed: int | Unknown
+    reveal_type(r)  # revealed: @Todo(unknown type subscript)
 ```

 ## Invalid Collection based AST nodes
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/literal_string.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/literal_string.md
@@ -38,12 +38,8 @@ bad_nesting: Literal[LiteralString]  # error: [invalid-type-form]
 ```py
 from typing_extensions import LiteralString

-# error: [invalid-type-form]
-a: LiteralString[str]
-
-# error: [invalid-type-form]
-# error: [unresolved-reference] "Name `foo` used when not defined"
-b: LiteralString["foo"]
+a: LiteralString[str]  # error: [invalid-type-form]
+b: LiteralString["foo"]  # error: [invalid-type-form]
 ```

 ### As a base class
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/stdlib_typing_aliases.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/stdlib_typing_aliases.md
@@ -106,13 +106,13 @@ reveal_type(ChainMapSubclass.__mro__)
 class CounterSubclass(typing.Counter): ...

 # TODO: Should be (CounterSubclass, Counter, dict, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
-# revealed: tuple[Literal[CounterSubclass], Literal[Counter], @Todo(GenericAlias instance), @Todo(`Generic[]` subscript), Literal[object]]
+# revealed: tuple[Literal[CounterSubclass], Literal[Counter], Unknown, Literal[object]]
 reveal_type(CounterSubclass.__mro__)

 class DefaultDictSubclass(typing.DefaultDict): ...

 # TODO: Should be (DefaultDictSubclass, defaultdict, dict, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
-# revealed: tuple[Literal[DefaultDictSubclass], Literal[defaultdict], @Todo(GenericAlias instance), Literal[object]]
+# revealed: tuple[Literal[DefaultDictSubclass], Literal[defaultdict], Unknown, Literal[object]]
 reveal_type(DefaultDictSubclass.__mro__)

 class DequeSubclass(typing.Deque): ...
@@ -124,6 +124,6 @@ reveal_type(DequeSubclass.__mro__)
 class OrderedDictSubclass(typing.OrderedDict): ...

 # TODO: Should be (OrderedDictSubclass, OrderedDict, dict, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
-# revealed: tuple[Literal[OrderedDictSubclass], Literal[OrderedDict], @Todo(GenericAlias instance), Literal[object]]
+# revealed: tuple[Literal[OrderedDictSubclass], Literal[OrderedDict], Unknown, Literal[object]]
 reveal_type(OrderedDictSubclass.__mro__)
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_special_forms.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_special_forms.md
@@ -89,12 +89,9 @@ python-version = "3.12"
 Some of these are not subscriptable:

 ```py
-from typing_extensions import Self, TypeAlias, TypeVar
+from typing_extensions import Self, TypeAlias

-T = TypeVar("T")
-
-# error: [invalid-type-form] "Special form `typing.TypeAlias` expected no type parameter"
-X: TypeAlias[T] = int
+X: TypeAlias[T] = int  # error: [invalid-type-form]

 class Foo[T]:
    # error: [invalid-type-form] "Special form `typing.Self` expected no type parameter"
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_type_qualifiers.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_type_qualifiers.md
@@ -11,6 +11,8 @@ from typing_extensions import Final, Required, NotRequired, ReadOnly, TypedDict
 X: Final = 42
 Y: Final[int] = 42

+# TODO: `TypedDict` is actually valid as a base
+# error: [invalid-base]
 class Bar(TypedDict):
    x: Required[int]
    y: NotRequired[str]
--- a/crates/red_knot_python_semantic/resources/mdtest/boundness_declaredness/public.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/boundness_declaredness/public.md
@@ -292,66 +292,3 @@ reveal_type(a)  # revealed: Unknown
 # Modifications allowed in this case:
 a = None
 ```
-
-## In stub files
-
-In stub files, we have a minor modification to the rules above: we do not union with `Unknown` for
-undeclared symbols.
-
-### Undeclared and bound
-
-`mod.pyi`:
-
-```pyi
-MyInt = int
-
-class C:
-    MyStr = str
-```
-
-```py
-from mod import MyInt, C
-
-reveal_type(MyInt)  # revealed: Literal[int]
-reveal_type(C.MyStr)  # revealed: Literal[str]
-```
-
-### Undeclared and possibly unbound
-
-`mod.pyi`:
-
-```pyi
-def flag() -> bool:
-    return True
-
-if flag():
-    MyInt = int
-
-    class C:
-        MyStr = str
-```
-
-```py
-# error: [possibly-unbound-import]
-# error: [possibly-unbound-import]
-from mod import MyInt, C
-
-reveal_type(MyInt)  # revealed: Literal[int]
-reveal_type(C.MyStr)  # revealed: Literal[str]
-```
-
-### Undeclared and unbound
-
-`mod.pyi`:
-
-```pyi
-if False:
-    MyInt = int
-```
-
-```py
-# error: [unresolved-import]
-from mod import MyInt
-
-reveal_type(MyInt)  # revealed: Unknown
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/call/union.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/union.md
@@ -162,44 +162,6 @@ def _(flag: bool):
    reveal_type(f("string"))  # revealed: Literal["string", "'string'"]
 ```

-## Unions with literals and negations
-
-```py
-from typing import Literal
-from knot_extensions import Not, AlwaysFalsy, static_assert, is_subtype_of, is_assignable_to
-
-static_assert(is_subtype_of(Literal["a", ""], Literal["a", ""] | Not[AlwaysFalsy]))
-static_assert(is_subtype_of(Not[AlwaysFalsy], Literal["", "a"] | Not[AlwaysFalsy]))
-static_assert(is_subtype_of(Literal["a", ""], Not[AlwaysFalsy] | Literal["a", ""]))
-static_assert(is_subtype_of(Not[AlwaysFalsy], Not[AlwaysFalsy] | Literal["a", ""]))
-
-static_assert(is_subtype_of(Literal["a", ""], Literal["a", ""] | Not[Literal[""]]))
-static_assert(is_subtype_of(Not[Literal[""]], Literal["a", ""] | Not[Literal[""]]))
-static_assert(is_subtype_of(Literal["a", ""], Not[Literal[""]] | Literal["a", ""]))
-static_assert(is_subtype_of(Not[Literal[""]], Not[Literal[""]] | Literal["a", ""]))
-
-def _(
-    a: Literal["a", ""] | Not[AlwaysFalsy],
-    b: Literal["a", ""] | Not[Literal[""]],
-    c: Literal[""] | Not[Literal[""]],
-    d: Not[Literal[""]] | Literal[""],
-    e: Literal["a"] | Not[Literal["a"]],
-    f: Literal[b"b"] | Not[Literal[b"b"]],
-    g: Not[Literal[b"b"]] | Literal[b"b"],
-    h: Literal[42] | Not[Literal[42]],
-    i: Not[Literal[42]] | Literal[42],
-):
-    reveal_type(a)  # revealed: Literal[""] | ~AlwaysFalsy
-    reveal_type(b)  # revealed: object
-    reveal_type(c)  # revealed: object
-    reveal_type(d)  # revealed: object
-    reveal_type(e)  # revealed: object
-    reveal_type(f)  # revealed: object
-    reveal_type(g)  # revealed: object
-    reveal_type(h)  # revealed: object
-    reveal_type(i)  # revealed: object
-```
-
 ## Cannot use an argument as both a value and a type form

 ```py
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/integers.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/integers.md
@@ -13,7 +13,7 @@ reveal_type(1 is not 1)  # revealed: bool
 reveal_type(1 is 2)  # revealed: Literal[False]
 reveal_type(1 is not 7)  # revealed: Literal[True]
 # error: [unsupported-operator] "Operator `<=` is not supported for types `int` and `str`, in comparing `Literal[1]` with `Literal[""]`"
-reveal_type(1 <= "" and 0 < 1)  # revealed: (Unknown & ~AlwaysTruthy) | Literal[True]
+reveal_type(1 <= "" and 0 < 1)  # revealed: Unknown & ~AlwaysTruthy | Literal[True]
 ```

 ## Integer instance
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/non_bool_returns.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/non_bool_returns.md
@@ -37,7 +37,7 @@ class C:
        return self

 x = A() < B() < C()
-reveal_type(x)  # revealed: (A & ~AlwaysTruthy) | B
+reveal_type(x)  # revealed: A & ~AlwaysTruthy | B

 y = 0 < 1 < A() < 3
 reveal_type(y)  # revealed: Literal[False] | A
--- a/crates/red_knot_python_semantic/resources/mdtest/comprehensions/basic.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comprehensions/basic.md
@@ -127,9 +127,8 @@ class AsyncIterable:
    def __aiter__(self) -> AsyncIterator:
        return AsyncIterator()

-async def _():
-    # revealed: @Todo(async iterables/iterators)
-    [reveal_type(x) async for x in AsyncIterable()]
+# revealed: @Todo(async iterables/iterators)
+[reveal_type(x) async for x in AsyncIterable()]
 ```

 ### Invalid async comprehension
@@ -146,7 +145,6 @@ class Iterable:
    def __iter__(self) -> Iterator:
        return Iterator()

-async def _():
-    # revealed: @Todo(async iterables/iterators)
-    [reveal_type(x) async for x in Iterable()]
+# revealed: @Todo(async iterables/iterators)
+[reveal_type(x) async for x in Iterable()]
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/conditional/if_expression.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/conditional/if_expression.md
@@ -42,6 +42,6 @@ def _(flag: bool):
 class NotBoolable:
    __bool__: int = 3

-# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`"
+# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
 3 if NotBoolable() else 4
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/conditional/if_statement.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/conditional/if_statement.md
@@ -154,10 +154,10 @@ def _(flag: bool):
 class NotBoolable:
    __bool__: int = 3

-# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`"
+# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
 if NotBoolable():
    ...
-# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`"
+# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
 elif NotBoolable():
    ...
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/conditional/match.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/conditional/match.md
@@ -292,7 +292,7 @@ class NotBoolable:
 def _(target: int, flag: NotBoolable):
    y = 1
    match target:
-        # error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`"
+        # error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
        case 1 if flag:
            y = 2
        case 2:
--- a/crates/red_knot_python_semantic/resources/mdtest/dataclass_transform.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/dataclass_transform.md
@@ -1,293 +0,0 @@
-# `typing.dataclass_transform`
-
-```toml
-[environment]
-python-version = "3.12"
-```
-
-`dataclass_transform` is a decorator that can be used to let type checkers know that a function,
-class, or metaclass is a `dataclass`-like construct.
-
-## Basic example
-
-```py
-from typing_extensions import dataclass_transform
-
-@dataclass_transform()
-def my_dataclass[T](cls: type[T]) -> type[T]:
-    # modify cls
-    return cls
-
-@my_dataclass
-class Person:
-    name: str
-    age: int | None = None
-
-Person("Alice", 20)
-Person("Bob", None)
-Person("Bob")
-
-# error: [missing-argument]
-Person()
-```
-
-## Decorating decorators that take parameters themselves
-
-If we want our `dataclass`-like decorator to also take parameters, that is also possible:
-
-```py
-from typing_extensions import dataclass_transform, Callable
-
-@dataclass_transform()
-def versioned_class[T](*, version: int = 1):
-    def decorator(cls):
-        # modify cls
-        return cls
-    return decorator
-
-@versioned_class(version=2)
-class Person:
-    name: str
-    age: int | None = None
-
-Person("Alice", 20)
-
-# error: [missing-argument]
-Person()
-```
-
-We properly type-check the arguments to the decorator:
-
-```py
-from typing_extensions import dataclass_transform, Callable
-
-# error: [invalid-argument-type]
-@versioned_class(version="a string")
-class C:
-    name: str
-```
-
-## Types of decorators
-
-The examples from this section are straight from the Python documentation on
-[`typing.dataclass_transform`].
-
-### Decorating a decorator function
-
-```py
-from typing_extensions import dataclass_transform
-
-@dataclass_transform()
-def create_model[T](cls: type[T]) -> type[T]:
-    ...
-    return cls
-
-@create_model
-class CustomerModel:
-    id: int
-    name: str
-
-CustomerModel(id=1, name="Test")
-```
-
-### Decorating a metaclass
-
-```py
-from typing_extensions import dataclass_transform
-
-@dataclass_transform()
-class ModelMeta(type): ...
-
-class ModelBase(metaclass=ModelMeta): ...
-
-class CustomerModel(ModelBase):
-    id: int
-    name: str
-
-CustomerModel(id=1, name="Test")
-
-# error: [missing-argument]
-CustomerModel()
-```
-
-### Decorating a base class
-
-```py
-from typing_extensions import dataclass_transform
-
-@dataclass_transform()
-class ModelBase: ...
-
-class CustomerModel(ModelBase):
-    id: int
-    name: str
-
-# TODO: this is not supported yet
-# error: [unknown-argument]
-# error: [unknown-argument]
-CustomerModel(id=1, name="Test")
-```
-
-## Arguments to `dataclass_transform`
-
-### `eq_default`
-
-`eq=True/False` does not have a observable effect (apart from a minor change regarding whether
-`other` is positional-only or not, which is not modelled at the moment).
-
-### `order_default`
-
-The `order_default` argument controls whether methods such as `__lt__` are generated by default.
-This can be overwritten using the `order` argument to the custom decorator:
-
-```py
-from typing_extensions import dataclass_transform
-
-@dataclass_transform()
-def normal(*, order: bool = False):
-    raise NotImplementedError
-
-@dataclass_transform(order_default=False)
-def order_default_false(*, order: bool = False):
-    raise NotImplementedError
-
-@dataclass_transform(order_default=True)
-def order_default_true(*, order: bool = True):
-    raise NotImplementedError
-
-@normal
-class Normal:
-    inner: int
-
-Normal(1) < Normal(2)  # error: [unsupported-operator]
-
-@normal(order=True)
-class NormalOverwritten:
-    inner: int
-
-NormalOverwritten(1) < NormalOverwritten(2)
-
-@order_default_false
-class OrderFalse:
-    inner: int
-
-OrderFalse(1) < OrderFalse(2)  # error: [unsupported-operator]
-
-@order_default_false(order=True)
-class OrderFalseOverwritten:
-    inner: int
-
-OrderFalseOverwritten(1) < OrderFalseOverwritten(2)
-
-@order_default_true
-class OrderTrue:
-    inner: int
-
-OrderTrue(1) < OrderTrue(2)
-
-@order_default_true(order=False)
-class OrderTrueOverwritten:
-    inner: int
-
-# error: [unsupported-operator]
-OrderTrueOverwritten(1) < OrderTrueOverwritten(2)
-```
-
-### `kw_only_default`
-
-To do
-
-### `field_specifiers`
-
-To do
-
-## Overloaded dataclass-like decorators
-
-In the case of an overloaded decorator, the `dataclass_transform` decorator can be applied to the
-implementation, or to *one* of the overloads.
-
-### Applying `dataclass_transform` to the implementation
-
-```py
-from typing_extensions import dataclass_transform, TypeVar, Callable, overload
-
-T = TypeVar("T", bound=type)
-
-@overload
-def versioned_class(
-    cls: T,
-    *,
-    version: int = 1,
-) -> T: ...
-@overload
-def versioned_class(
-    *,
-    version: int = 1,
-) -> Callable[[T], T]: ...
-@dataclass_transform()
-def versioned_class(
-    cls: T | None = None,
-    *,
-    version: int = 1,
-) -> T | Callable[[T], T]:
-    raise NotImplementedError
-
-@versioned_class
-class D1:
-    x: str
-
-@versioned_class(version=2)
-class D2:
-    x: str
-
-D1("a")
-D2("a")
-
-D1(1.2)  # error: [invalid-argument-type]
-D2(1.2)  # error: [invalid-argument-type]
-```
-
-### Applying `dataclass_transform` to an overload
-
-```py
-from typing_extensions import dataclass_transform, TypeVar, Callable, overload
-
-T = TypeVar("T", bound=type)
-
-@overload
-@dataclass_transform()
-def versioned_class(
-    cls: T,
-    *,
-    version: int = 1,
-) -> T: ...
-@overload
-def versioned_class(
-    *,
-    version: int = 1,
-) -> Callable[[T], T]: ...
-def versioned_class(
-    cls: T | None = None,
-    *,
-    version: int = 1,
-) -> T | Callable[[T], T]:
-    raise NotImplementedError
-
-@versioned_class
-class D1:
-    x: str
-
-@versioned_class(version=2)
-class D2:
-    x: str
-
-# TODO: these should not be errors
-D1("a")  # error: [too-many-positional-arguments]
-D2("a")  # error: [too-many-positional-arguments]
-
-# TODO: these should be invalid-argument-type errors
-D1(1.2)  # error: [too-many-positional-arguments]
-D2(1.2)  # error: [too-many-positional-arguments]
-```
-
-[`typing.dataclass_transform`]: https://docs.python.org/3/library/typing.html#typing.dataclass_transform
--- a/crates/red_knot_python_semantic/resources/mdtest/dataclasses.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/dataclasses.md
@@ -689,7 +689,7 @@ from dataclasses import dataclass

 dataclass_with_order = dataclass(order=True)

-reveal_type(dataclass_with_order)  # revealed: <decorator produced by dataclass-like function>
+reveal_type(dataclass_with_order)  # revealed: <decorator produced by dataclasses.dataclass>

@dataclass_with_order
 class C:
--- a/crates/red_knot_python_semantic/resources/mdtest/diagnostics/semantic_syntax_errors.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/diagnostics/semantic_syntax_errors.md
@@ -1,165 +0,0 @@
-# Semantic syntax error diagnostics
-
-## `async` comprehensions in synchronous comprehensions
-
-### Python 3.10
-
-<!-- snapshot-diagnostics -->
-
-Before Python 3.11, `async` comprehensions could not be used within outer sync comprehensions, even
-within an `async` function ([CPython issue](https://github.com/python/cpython/issues/77527)):
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-async def elements(n):
-    yield n
-
-async def f():
-    # error: 19 [invalid-syntax] "cannot use an asynchronous comprehension inside of a synchronous comprehension on Python 3.10 (syntax was added in 3.11)"
-    return {n: [x async for x in elements(n)] for n in range(3)}
-```
-
-If all of the comprehensions are `async`, on the other hand, the code was still valid:
-
-```py
-async def test():
-    return [[x async for x in elements(n)] async for n in range(3)]
-```
-
-These are a couple of tricky but valid cases to check that nested scope handling is wired up
-correctly in the `SemanticSyntaxContext` trait:
-
-```py
-async def f():
-    [x for x in [1]] and [x async for x in elements(1)]
-
-async def f():
-    def g():
-        pass
-    [x async for x in elements(1)]
-```
-
-### Python 3.11
-
-All of these same examples are valid after Python 3.11:
-
-```toml
-[environment]
-python-version = "3.11"
-```
-
-```py
-async def elements(n):
-    yield n
-
-async def f():
-    return {n: [x async for x in elements(n)] for n in range(3)}
-```
-
-## Late `__future__` import
-
-```py
-from collections import namedtuple
-
-# error: [invalid-syntax] "__future__ imports must be at the top of the file"
-from __future__ import print_function
-```
-
-## Invalid annotation
-
-This one might be a bit redundant with the `invalid-type-form` error.
-
-```toml
-[environment]
-python-version = "3.12"
-```
-
-```py
-from __future__ import annotations
-
-# error: [invalid-type-form] "Named expressions are not allowed in type expressions"
-# error: [invalid-syntax] "named expression cannot be used within a type annotation"
-def f() -> (y := 3): ...
-```
-
-## Duplicate `match` key
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-match 2:
-    # error: [invalid-syntax] "mapping pattern checks duplicate key `"x"`"
-    case {"x": 1, "x": 2}:
-        ...
-```
-
-## `return`, `yield`, `yield from`, and `await` outside function
-
-```py
-# error: [invalid-syntax] "`return` statement outside of a function"
-return
-
-# error: [invalid-syntax] "`yield` statement outside of a function"
-yield
-
-# error: [invalid-syntax] "`yield from` statement outside of a function"
-yield from []
-
-# error: [invalid-syntax] "`await` statement outside of a function"
-# error: [invalid-syntax] "`await` outside of an asynchronous function"
-await 1
-
-def f():
-    # error: [invalid-syntax] "`await` outside of an asynchronous function"
-    await 1
-```
-
-Generators are evaluated lazily, so `await` is allowed, even outside of a function.
-
-```py
-async def g():
-    yield 1
-
-(x async for x in g())
-```
-
-## `await` outside async function
-
-This error includes `await`, `async for`, `async with`, and `async` comprehensions.
-
-```python
-async def elements(n):
-    yield n
-
-def _():
-    # error: [invalid-syntax] "`await` outside of an asynchronous function"
-    await 1
-    # error: [invalid-syntax] "`async for` outside of an asynchronous function"
-    async for _ in elements(1):
-        ...
-    # error: [invalid-syntax] "`async with` outside of an asynchronous function"
-    async with elements(1) as x:
-        ...
-    # error: [invalid-syntax] "cannot use an asynchronous comprehension outside of an asynchronous function on Python 3.9 (syntax was added in 3.11)"
-    # error: [invalid-syntax] "asynchronous comprehension outside of an asynchronous function"
-    [x async for x in elements(1)]
-```
-
-## Load before `global` declaration
-
-This should be an error, but it's not yet.
-
-TODO implement `SemanticSyntaxContext::global`
-
-```py
-def f():
-    x = 1
-    global x
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/diagnostics/shadowing.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/diagnostics/shadowing.md
@@ -1,19 +0,0 @@
-# Shadowing
-
-<!-- snapshot-diagnostics -->
-
-## Implicit class shadowing
-
-```py
-class C: ...
-
-C = 1  # error: [invalid-assignment]
-```
-
-## Implicit function shadowing
-
-```py
-def f(): ...
-
-f = 1  # error: [invalid-assignment]
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/diagnostics/unpacking.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/diagnostics/unpacking.md
@@ -8,20 +8,14 @@
 a, b = 1  # error: [not-iterable]
 ```

-## Exactly too many values to unpack
+## Too many values to unpack

 ```py
 a, b = (1, 2, 3)  # error: [invalid-assignment]
 ```

-## Exactly too few values to unpack
+## Too few values to unpack

 ```py
 a, b = (1,)  # error: [invalid-assignment]
 ```
-
-## Too few values to unpack
-
-```py
-[a, *b, c, d] = (1, 2)  # error: [invalid-assignment]
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/diagnostics/unsupported_bool_conversion.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/diagnostics/unsupported_bool_conversion.md
@@ -1,61 +0,0 @@
-<!-- snapshot-diagnostics -->
-
-# Different ways that `unsupported-bool-conversion` can occur
-
-## Has a `__bool__` method, but has incorrect parameters
-
-```py
-class NotBoolable:
-    def __bool__(self, foo):
-        return False
-
-a = NotBoolable()
-
-# error: [unsupported-bool-conversion]
-10 and a and True
-```
-
-## Has a `__bool__` method, but has an incorrect return type
-
-```py
-class NotBoolable:
-    def __bool__(self) -> str:
-        return "wat"
-
-a = NotBoolable()
-
-# error: [unsupported-bool-conversion]
-10 and a and True
-```
-
-## Has a `__bool__` attribute, but it's not callable
-
-```py
-class NotBoolable:
-    __bool__: int = 3
-
-a = NotBoolable()
-
-# error: [unsupported-bool-conversion]
-10 and a and True
-```
-
-## Part of a union where at least one member has incorrect `__bool__` method
-
-```py
-class NotBoolable1:
-    def __bool__(self) -> str:
-        return "wat"
-
-class NotBoolable2:
-    pass
-
-class NotBoolable3:
-    __bool__: int = 3
-
-def get() -> NotBoolable1 | NotBoolable2 | NotBoolable3:
-    return NotBoolable2()
-
-# error: [unsupported-bool-conversion]
-10 and get() and True
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/expression/assert.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/expression/assert.md
@@ -4,6 +4,6 @@
 class NotBoolable:
    __bool__: int = 3

-# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`"
+# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
 assert NotBoolable()
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/expression/boolean.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/expression/boolean.md
@@ -10,8 +10,8 @@ def _(foo: str):
    reveal_type(False or "z")  # revealed: Literal["z"]
    reveal_type(False or True)  # revealed: Literal[True]
    reveal_type(False or False)  # revealed: Literal[False]
-    reveal_type(foo or False)  # revealed: (str & ~AlwaysFalsy) | Literal[False]
-    reveal_type(foo or True)  # revealed: (str & ~AlwaysFalsy) | Literal[True]
+    reveal_type(foo or False)  # revealed: str & ~AlwaysFalsy | Literal[False]
+    reveal_type(foo or True)  # revealed: str & ~AlwaysFalsy | Literal[True]
 ```

 ## AND
@@ -20,8 +20,8 @@ def _(foo: str):
 def _(foo: str):
    reveal_type(True and False)  # revealed: Literal[False]
    reveal_type(False and True)  # revealed: Literal[False]
-    reveal_type(foo and False)  # revealed: (str & ~AlwaysTruthy) | Literal[False]
-    reveal_type(foo and True)  # revealed: (str & ~AlwaysTruthy) | Literal[True]
+    reveal_type(foo and False)  # revealed: str & ~AlwaysTruthy | Literal[False]
+    reveal_type(foo and True)  # revealed: str & ~AlwaysTruthy | Literal[True]
    reveal_type("x" and "y" and "z")  # revealed: Literal["z"]
    reveal_type("x" and "y" and "")  # revealed: Literal[""]
    reveal_type("" and "y")  # revealed: Literal[""]
@@ -123,7 +123,7 @@ if NotBoolable():
 class NotBoolable:
    __bool__: None = None

-# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`"
+# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
 if NotBoolable():
    ...
 ```
@@ -135,7 +135,7 @@ def test(cond: bool):
    class NotBoolable:
        __bool__: int | None = None if cond else 3

-    # error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`"
+    # error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
    if NotBoolable():
        ...
 ```
@@ -149,7 +149,7 @@ def test(cond: bool):

    a = 10 if cond else NotBoolable()

-    # error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `Literal[10] | NotBoolable`"
+    # error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `Literal[10] | NotBoolable`; its `__bool__` method isn't callable"
    if a:
        ...
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/generics/classes.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/generics/classes.md
@@ -232,11 +232,21 @@ TODO: These do not currently work yet, because we don't correctly model the nest
 class C[T]:
    def __init__[S](self, x: T, y: S) -> None: ...

-reveal_type(C(1, 1))  # revealed: C[Literal[1]]
-reveal_type(C(1, "string"))  # revealed: C[Literal[1]]
-reveal_type(C(1, True))  # revealed: C[Literal[1]]
+# TODO: no error
+# TODO: revealed: C[Literal[1]]
+# error: [invalid-argument-type]
+reveal_type(C(1, 1))  # revealed: C[Unknown]
+# TODO: no error
+# TODO: revealed: C[Literal[1]]
+# error: [invalid-argument-type]
+reveal_type(C(1, "string"))  # revealed: C[Unknown]
+# TODO: no error
+# TODO: revealed: C[Literal[1]]
+# error: [invalid-argument-type]
+reveal_type(C(1, True))  # revealed: C[Unknown]

-# error: [invalid-assignment] "Object of type `C[Literal["five"]]` is not assignable to `C[int]`"
+# TODO: [invalid-assignment] "Object of type `C[Literal["five"]]` is not assignable to `C[int]`"
+# error: [invalid-argument-type] "Argument to this function is incorrect: Expected `S`, found `Literal[1]`"
 wrong_innards: C[int] = C("five", 1)
 ```

@@ -275,17 +285,15 @@ c: C[int] = C[int]()
 reveal_type(c.method("string"))  # revealed: Literal["string"]
 ```

-## Cyclic class definitions
-
-### F-bounded quantification
+## Cyclic class definition

 A class can use itself as the type parameter of one of its superclasses. (This is also known as the
 [curiously recurring template pattern][crtp] or [F-bounded quantification][f-bound].)

-#### In a stub file
-
 Here, `Sub` is not a generic class, since it fills its superclass's type parameter (with itself).

+`stub.pyi`:
+
 ```pyi
 class Base[T]: ...
 class Sub(Base[Sub]): ...
@@ -293,10 +301,10 @@ class Sub(Base[Sub]): ...
 reveal_type(Sub)  # revealed: Literal[Sub]
 ```

-#### With string forward references
-
 A similar case can work in a non-stub file, if forward references are stringified:

+`string_annotation.py`:
+
 ```py
 class Base[T]: ...
 class Sub(Base["Sub"]): ...
@@ -304,10 +312,10 @@ class Sub(Base["Sub"]): ...
 reveal_type(Sub)  # revealed: Literal[Sub]
 ```

-#### Without string forward references
-
 In a non-stub file, without stringified forward references, this raises a `NameError`:

+`bare_annotation.py`:
+
 ```py
 class Base[T]: ...

@@ -315,23 +323,13 @@ class Base[T]: ...
 class Sub(Base[Sub]): ...
 ```

-### Cyclic inheritance as a generic parameter
+## Another cyclic case

 ```pyi
+# TODO no error (generics)
+# error: [invalid-base]
 class Derived[T](list[Derived[T]]): ...
 ```

-### Direct cyclic inheritance
-
-Inheritance that would result in a cyclic MRO is detected as an error.
-
-```py
-# error: [cyclic-class-definition]
-class C[T](C): ...
-
-# error: [cyclic-class-definition]
-class D[T](D[int]): ...
-```
-
 [crtp]: https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern
 [f-bound]: https://en.wikipedia.org/wiki/Bounded_quantification#F-bounded_quantification
--- a/crates/red_knot_python_semantic/resources/mdtest/import/builtins.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/import/builtins.md
@@ -7,7 +7,7 @@ Builtin symbols can be explicitly imported:
 ```py
 import builtins

-reveal_type(builtins.chr)  # revealed: def chr(i: SupportsIndex, /) -> str
+reveal_type(builtins.chr)  # revealed: def chr(i: int | SupportsIndex, /) -> str
 ```

 ## Implicit use of builtin
@@ -15,7 +15,7 @@ reveal_type(builtins.chr)  # revealed: def chr(i: SupportsIndex, /) -> str
 Or used implicitly:

 ```py
-reveal_type(chr)  # revealed: def chr(i: SupportsIndex, /) -> str
+reveal_type(chr)  # revealed: def chr(i: int | SupportsIndex, /) -> str
 reveal_type(str)  # revealed: Literal[str]
 ```

--- a/crates/red_knot_python_semantic/resources/mdtest/import/star.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/import/star.md
@@ -189,7 +189,7 @@ match 42:
        ...
    case [O]:
        ...
-    case P | Q:  # error: [invalid-syntax] "name capture `P` makes remaining patterns unreachable"
+    case P | Q:
        ...
    case object(foo=R):
        ...
@@ -289,7 +289,7 @@ match 42:
        ...
    case [D]:
        ...
-    case E | F:  # error: [invalid-syntax] "name capture `E` makes remaining patterns unreachable"
+    case E | F:
        ...
    case object(foo=G):
        ...
@@ -357,7 +357,7 @@ match 42:
        ...
    case [D]:
        ...
-    case E | F:  # error: [invalid-syntax] "name capture `E` makes remaining patterns unreachable"
+    case E | F:
        ...
    case object(foo=G):
        ...
--- a/crates/red_knot_python_semantic/resources/mdtest/intersection_types.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/intersection_types.md
@@ -191,9 +191,9 @@ def _(
    i2: Intersection[P | Q | R, S],
    i3: Intersection[P | Q, R | S],
 ) -> None:
-    reveal_type(i1)  # revealed: (P & Q) | (P & R) | (P & S)
-    reveal_type(i2)  # revealed: (P & S) | (Q & S) | (R & S)
-    reveal_type(i3)  # revealed: (P & R) | (Q & R) | (P & S) | (Q & S)
+    reveal_type(i1)  # revealed: P & Q | P & R | P & S
+    reveal_type(i2)  # revealed: P & S | Q & S | R & S
+    reveal_type(i3)  # revealed: P & R | Q & R | P & S | Q & S

 def simplifications_for_same_elements(
    i1: Intersection[P, Q | P],
@@ -216,7 +216,7 @@ def simplifications_for_same_elements(
    # = P & Q | P & R | Q | Q & R
    # = Q | P & R
    # (again, because Q is a supertype of P & Q and of Q & R)
-    reveal_type(i3)  # revealed: Q | (P & R)
+    reveal_type(i3)  # revealed: Q | P & R

    #   (P | Q) & (P | Q)
    # = P & P | P & Q | Q & P | Q & Q
--- a/crates/red_knot_python_semantic/resources/mdtest/loops/while_loop.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/loops/while_loop.md
@@ -123,7 +123,7 @@ def _(flag: bool, flag2: bool):
 class NotBoolable:
    __bool__: int = 3

-# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`"
+# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
 while NotBoolable():
    ...
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/mdtest_custom_typeshed.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/mdtest_custom_typeshed.md
@@ -22,7 +22,6 @@ We can then place custom stub files in `/typeshed/stdlib`, for example:
 `/typeshed/stdlib/builtins.pyi`:

 ```pyi
-class object: ...
 class BuiltinClass: ...

 builtin_symbol: BuiltinClass
--- a/crates/red_knot_python_semantic/resources/mdtest/metaclass.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/metaclass.md
@@ -53,25 +53,6 @@ class B(A): ...
 reveal_type(B.__class__)  # revealed: Literal[M]
 ```

-## Linear inheritance with PEP 695 generic class
-
-The same is true if the base with the metaclass is a generic class.
-
-```toml
-[environment]
-python-version = "3.13"
-```
-
-```py
-class M(type): ...
-class A[T](metaclass=M): ...
-class B(A): ...
-class C(A[int]): ...
-
-reveal_type(B.__class__)  # revealed: Literal[M]
-reveal_type(C.__class__)  # revealed: Literal[M]
-```
-
 ## Conflict (1)

 The metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its
--- a/crates/red_knot_python_semantic/resources/mdtest/mro.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/mro.md
@@ -191,8 +191,8 @@ reveal_type(AA.__mro__)  # revealed: tuple[Literal[AA], Literal[Z], Unknown, Lit

 ## `__bases__` includes a `Union`

-We don't support union types in a class's bases; a base must resolve to a single `ClassType`. If we
-find a union type in a class's bases, we infer the class's `__mro__` as being
+We don't support union types in a class's bases; a base must resolve to a single `ClassLiteralType`.
+If we find a union type in a class's bases, we infer the class's `__mro__` as being
 `[<class>, Unknown, object]`, the same as for MROs that cause errors at runtime.

 ```py
--- a/crates/red_knot_python_semantic/resources/mdtest/narrow/assert.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/narrow/assert.md
@@ -29,7 +29,7 @@ def _(x: Literal[1, 2, 3], y: Literal[1, 2, 3]):
    assert x is 2
    reveal_type(x)  # revealed: Literal[2]
    assert y == 2
-    reveal_type(y)  # revealed: Literal[2]
+    reveal_type(y)  # revealed: Literal[1, 2, 3]
 ```

 ## `assert` with `isinstance`
--- a/crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/boolean.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/boolean.md
@@ -10,7 +10,7 @@ def _(x: A | B):
    if isinstance(x, A) and isinstance(x, B):
        reveal_type(x)  # revealed:  A & B
    else:
-        reveal_type(x)  # revealed:  (B & ~A) | (A & ~B)
+        reveal_type(x)  # revealed:  B & ~A | A & ~B
 ```

 ## Arms might not add narrowing constraints
@@ -131,8 +131,8 @@ def _(x: A | B | C, y: A | B | C):
        # The same for `y`
        reveal_type(y)  # revealed:  A | B | C
    else:
-        reveal_type(x)  # revealed:  (B & ~A) | (C & ~A)
-        reveal_type(y)  # revealed:  (B & ~A) | (C & ~A)
+        reveal_type(x)  # revealed:  B & ~A | C & ~A
+        reveal_type(y)  # revealed:  B & ~A | C & ~A

    if (isinstance(x, A) and isinstance(y, A)) or (isinstance(x, B) and isinstance(y, B)):
        # Here, types of `x` and `y` can be narrowd since all `or` arms constraint them.
@@ -155,7 +155,7 @@ def _(x: A | B | C):
        reveal_type(x)  # revealed:  B & ~C
    else:
        # ~(B & ~C) -> ~B | C -> (A & ~B) | (C & ~B) | C -> (A & ~B) | C
-        reveal_type(x)  # revealed: (A & ~B) | C
+        reveal_type(x)  # revealed: A & ~B | C
 ```

 ## mixing `or` and `not`
@@ -167,7 +167,7 @@ class C: ...

 def _(x: A | B | C):
    if isinstance(x, B) or not isinstance(x, C):
-        reveal_type(x)  # revealed: B | (A & ~C)
+        reveal_type(x)  # revealed: B | A & ~C
    else:
        reveal_type(x)  # revealed: C & ~B
 ```
@@ -181,7 +181,7 @@ class C: ...

 def _(x: A | B | C):
    if isinstance(x, A) or (isinstance(x, B) and not isinstance(x, C)):
-        reveal_type(x)  # revealed:  A | (B & ~C)
+        reveal_type(x)  # revealed:  A | B & ~C
    else:
        # ~(A | (B & ~C)) -> ~A & ~(B & ~C) -> ~A & (~B | C) -> (~A & C) | (~A ~ B)
        reveal_type(x)  # revealed:  C & ~A
@@ -197,7 +197,7 @@ class C: ...
 def _(x: A | B | C):
    if isinstance(x, A) and (isinstance(x, B) or not isinstance(x, C)):
        # A & (B | ~C) -> (A & B) | (A & ~C)
-        reveal_type(x)  # revealed:  (A & B) | (A & ~C)
+        reveal_type(x)  # revealed:  A & B | A & ~C
    else:
        # ~((A & B) | (A & ~C)) ->
        # ~(A & B) & ~(A & ~C) ->
@@ -206,7 +206,7 @@ def _(x: A | B | C):
        # ~A | (~A & C) | (~B & C) ->
        # ~A | (C & ~B) ->
        # ~A | (C & ~B)  The positive side of ~A is  A | B | C ->
-        reveal_type(x)  # revealed:  (B & ~A) | (C & ~A) | (C & ~B)
+        reveal_type(x)  # revealed:  B & ~A | C & ~A | C & ~B
 ```

 ## Boolean expression internal narrowing
--- a/crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/elif_else.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/elif_else.md
@@ -20,9 +20,11 @@ def _(flag1: bool, flag2: bool):
    x = 1 if flag1 else 2 if flag2 else 3

    if x == 1:
-        reveal_type(x)  # revealed: Literal[1]
+        # TODO should be Literal[1]
+        reveal_type(x)  # revealed: Literal[1, 2, 3]
    elif x == 2:
-        reveal_type(x)  # revealed: Literal[2]
+        # TODO should be Literal[2]
+        reveal_type(x)  # revealed: Literal[2, 3]
    else:
        reveal_type(x)  # revealed: Literal[3]
 ```
@@ -36,11 +38,14 @@ def _(flag1: bool, flag2: bool):
    if x != 1:
        reveal_type(x)  # revealed: Literal[2, 3]
    elif x != 2:
-        reveal_type(x)  # revealed: Literal[1]
+        # TODO should be `Literal[1]`
+        reveal_type(x)  # revealed: Literal[1, 3]
    elif x == 3:
-        reveal_type(x)  # revealed: Never
+        # TODO should be Never
+        reveal_type(x)  # revealed: Literal[1, 2, 3]
    else:
-        reveal_type(x)  # revealed: Never
+        # TODO should be Never
+        reveal_type(x)  # revealed: Literal[1, 2]
 ```

 ## Assignment expressions
--- a/crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/nested.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/nested.md
@@ -31,14 +31,17 @@ def _(flag1: bool, flag2: bool):
    if x != 1:
        reveal_type(x)  # revealed: Literal[2, 3]
        if x == 2:
-            reveal_type(x)  # revealed: Literal[2]
+            # TODO should be `Literal[2]`
+            reveal_type(x)  # revealed: Literal[2, 3]
        elif x == 3:
            reveal_type(x)  # revealed: Literal[3]
        else:
            reveal_type(x)  # revealed: Never

    elif x != 2:
-        reveal_type(x)  # revealed: Literal[1]
+        # TODO should be Literal[1]
+        reveal_type(x)  # revealed: Literal[1, 3]
    else:
-        reveal_type(x)  # revealed: Never
+        # TODO should be Never
+        reveal_type(x)  # revealed: Literal[1, 2, 3]
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/not_eq.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/not_eq.md
@@ -9,7 +9,8 @@ def _(flag: bool):
    if x != None:
        reveal_type(x)  # revealed: Literal[1]
    else:
-        reveal_type(x)  # revealed: None
+        # TODO should be None
+        reveal_type(x)  # revealed: None | Literal[1]
 ```

 ## `!=` for other singleton types
@@ -21,7 +22,8 @@ def _(flag: bool):
    if x != False:
        reveal_type(x)  # revealed: Literal[True]
    else:
-        reveal_type(x)  # revealed: Literal[False]
+        # TODO should be Literal[False]
+        reveal_type(x)  # revealed: bool
 ```

 ## `x != y` where `y` is of literal type
@@ -45,7 +47,8 @@ def _(flag: bool):
    if C != A:
        reveal_type(C)  # revealed: Literal[B]
    else:
-        reveal_type(C)  # revealed: Literal[A]
+        # TODO should be Literal[A]
+        reveal_type(C)  # revealed: Literal[A, B]
 ```

 ## `x != y` where `y` has multiple single-valued options
@@ -58,7 +61,8 @@ def _(flag1: bool, flag2: bool):
    if x != y:
        reveal_type(x)  # revealed: Literal[1, 2]
    else:
-        reveal_type(x)  # revealed: Literal[2]
+        # TODO should be Literal[2]
+        reveal_type(x)  # revealed: Literal[1, 2]
 ```

 ## `!=` for non-single-valued types
@@ -97,61 +101,6 @@ def f() -> Literal[1, 2, 3]:
 if (x := f()) != 1:
    reveal_type(x)  # revealed: Literal[2, 3]
 else:
-    reveal_type(x)  # revealed: Literal[1]
-```
-
-## Union with `Any`
-
-```py
-from typing import Any
-
-def _(x: Any | None, y: Any | None):
-    if x != 1:
-        reveal_type(x)  # revealed: (Any & ~Literal[1]) | None
-    if y == 1:
-        reveal_type(y)  # revealed: Any & ~None
-```
-
-## Booleans and integers
-
-```py
-from typing import Literal
-
-def _(b: bool, i: Literal[1, 2]):
-    if b == 1:
-        reveal_type(b)  # revealed: Literal[True]
-    else:
-        reveal_type(b)  # revealed: Literal[False]
-
-    if b == 6:
-        reveal_type(b)  # revealed: Never
-    else:
-        reveal_type(b)  # revealed: bool
-
-    if b == 0:
-        reveal_type(b)  # revealed: Literal[False]
-    else:
-        reveal_type(b)  # revealed: Literal[True]
-
-    if i == True:
-        reveal_type(i)  # revealed: Literal[1]
-    else:
-        reveal_type(i)  # revealed: Literal[2]
-```
-
-## Narrowing `LiteralString` in union
-
-```py
-from typing_extensions import Literal, LiteralString, Any
-
-def _(s: LiteralString | None, t: LiteralString | Any):
-    if s == "foo":
-        reveal_type(s)  # revealed: Literal["foo"]
-
-    if s == 1:
-        reveal_type(s)  # revealed: Never
-
-    if t == "foo":
-        # TODO could be `Literal["foo"] | Any`
-        reveal_type(t)  # revealed: LiteralString | Any
+    # TODO should be Literal[1]
+    reveal_type(x)  # revealed: Literal[1, 2, 3]
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/narrow/truthiness.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/narrow/truthiness.md
@@ -82,19 +82,19 @@ class B: ...

 def f(x: A | B):
    if x:
-        reveal_type(x)  # revealed: (A & ~AlwaysFalsy) | (B & ~AlwaysFalsy)
+        reveal_type(x)  # revealed: A & ~AlwaysFalsy | B & ~AlwaysFalsy
    else:
-        reveal_type(x)  # revealed: (A & ~AlwaysTruthy) | (B & ~AlwaysTruthy)
+        reveal_type(x)  # revealed: A & ~AlwaysTruthy | B & ~AlwaysTruthy

    if x and not x:
-        reveal_type(x)  # revealed: (A & ~AlwaysFalsy & ~AlwaysTruthy) | (B & ~AlwaysFalsy & ~AlwaysTruthy)
+        reveal_type(x)  # revealed: A & ~AlwaysFalsy & ~AlwaysTruthy | B & ~AlwaysFalsy & ~AlwaysTruthy
    else:
        reveal_type(x)  # revealed: A | B

    if x or not x:
        reveal_type(x)  # revealed: A | B
    else:
-        reveal_type(x)  # revealed: (A & ~AlwaysTruthy & ~AlwaysFalsy) | (B & ~AlwaysTruthy & ~AlwaysFalsy)
+        reveal_type(x)  # revealed: A & ~AlwaysTruthy & ~AlwaysFalsy | B & ~AlwaysTruthy & ~AlwaysFalsy
 ```

 ### Truthiness of Types
@@ -111,9 +111,9 @@ x = int if flag() else str
 reveal_type(x)  # revealed: Literal[int, str]

 if x:
-    reveal_type(x)  # revealed: (Literal[int] & ~AlwaysFalsy) | (Literal[str] & ~AlwaysFalsy)
+    reveal_type(x)  # revealed: Literal[int] & ~AlwaysFalsy | Literal[str] & ~AlwaysFalsy
 else:
-    reveal_type(x)  # revealed: (Literal[int] & ~AlwaysTruthy) | (Literal[str] & ~AlwaysTruthy)
+    reveal_type(x)  # revealed: Literal[int] & ~AlwaysTruthy | Literal[str] & ~AlwaysTruthy
 ```

 ## Determined Truthiness
@@ -176,12 +176,12 @@ if isinstance(x, str) and not isinstance(x, B):

    z = x if flag() else y

-    reveal_type(z)  # revealed: (A & str & ~B) | Literal[0, 42, "", "hello"]
+    reveal_type(z)  # revealed: A & str & ~B | Literal[0, 42, "", "hello"]

    if z:
-        reveal_type(z)  # revealed: (A & str & ~B & ~AlwaysFalsy) | Literal[42, "hello"]
+        reveal_type(z)  # revealed: A & str & ~B & ~AlwaysFalsy | Literal[42, "hello"]
    else:
-        reveal_type(z)  # revealed: (A & str & ~B & ~AlwaysTruthy) | Literal[0, ""]
+        reveal_type(z)  # revealed: A & str & ~B & ~AlwaysTruthy | Literal[0, ""]
 ```

 ## Narrowing Multiple Variables
@@ -264,13 +264,13 @@ def _(
 ):
    reveal_type(ta)  # revealed: type[TruthyClass] | type[AmbiguousClass]
    if ta:
-        reveal_type(ta)  # revealed: type[TruthyClass] | (type[AmbiguousClass] & ~AlwaysFalsy)
+        reveal_type(ta)  # revealed: type[TruthyClass] | type[AmbiguousClass] & ~AlwaysFalsy

    reveal_type(af)  # revealed: type[AmbiguousClass] | type[FalsyClass]
    if af:
        reveal_type(af)  # revealed: type[AmbiguousClass] & ~AlwaysFalsy

-    # error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `MetaDeferred`"
+    # error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `MetaDeferred`; the return type of its bool method (`MetaAmbiguous`) isn't assignable to `bool"
    if d:
        # TODO: Should be `Unknown`
        reveal_type(d)  # revealed: type[DeferredClass] & ~AlwaysFalsy
@@ -296,12 +296,12 @@ def _(x: Literal[0, 1]):
    reveal_type(x and A())  # revealed: Literal[0] | A

 def _(x: str):
-    reveal_type(x or A())  # revealed: (str & ~AlwaysFalsy) | A
-    reveal_type(x and A())  # revealed: (str & ~AlwaysTruthy) | A
+    reveal_type(x or A())  # revealed: str & ~AlwaysFalsy | A
+    reveal_type(x and A())  # revealed: str & ~AlwaysTruthy | A

 def _(x: bool | str):
-    reveal_type(x or A())  # revealed: Literal[True] | (str & ~AlwaysFalsy) | A
-    reveal_type(x and A())  # revealed: Literal[False] | (str & ~AlwaysTruthy) | A
+    reveal_type(x or A())  # revealed: Literal[True] | str & ~AlwaysFalsy | A
+    reveal_type(x and A())  # revealed: Literal[False] | str & ~AlwaysTruthy | A

 class Falsy:
    def __bool__(self) -> Literal[False]:
--- a/crates/red_knot_python_semantic/resources/mdtest/narrow/type.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/narrow/type.md
@@ -127,7 +127,7 @@ class B: ...

 def _[T](x: A | B):
    if type(x) is A[str]:
-        reveal_type(x)  # revealed: (A[int] & A[Unknown]) | (B & A[Unknown])
+        reveal_type(x)  # revealed: A[int] & A[Unknown] | B & A[Unknown]
    else:
        reveal_type(x)  # revealed: A[int] | B
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/panic.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/panic.md
@@ -1,25 +0,0 @@
-# repro interned panic
-
-## before
-
-```toml
-log = "salsa=trace,red_knot_test,ruff_db=trace,red_knot_ide=trace,red_knot_project=trace"
-[environment]
-python-version = "3.9"
-```
-
-```py
-None
-```
-
-## after
-
-```toml
-log = "salsa=trace,red_knot_test,ruff_db=trace,red_knot_ide=trace,red_knot_project=trace"
-[environment]
-python-version = "3.10"
-```
-
-```py
-None
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/protocols.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/protocols.md
@@ -230,7 +230,7 @@ And it is also an error to use `Protocol` in type expressions:
 def f(
    x: Protocol,  # error: [invalid-type-form] "`typing.Protocol` is not allowed in type expressions"
    y: type[Protocol],  # TODO: should emit `[invalid-type-form]` here too
-):
+) -> None:
    reveal_type(x)  # revealed: Unknown

    # TODO: should be `type[Unknown]`
@@ -242,7 +242,7 @@ def f(
 Nonetheless, `Protocol` can still be used as the second argument to `issubclass()` at runtime:

 ```py
-# Could also be `Literal[True]`, but `bool` is fine:
+# TODO: should be `Literal[True]`
 reveal_type(issubclass(MyProtocol, Protocol))  # revealed: bool
 ```

@@ -266,7 +266,9 @@ class Bar(typing_extensions.Protocol):

 static_assert(typing_extensions.is_protocol(Foo))
 static_assert(typing_extensions.is_protocol(Bar))
-static_assert(is_equivalent_to(Foo, Bar))
+
+# TODO: should pass
+static_assert(is_equivalent_to(Foo, Bar))  # error: [static-assert-error]
 ```

 The same goes for `typing.runtime_checkable` and `typing_extensions.runtime_checkable`:
@@ -282,7 +284,9 @@ class RuntimeCheckableBar(typing_extensions.Protocol):

 static_assert(typing_extensions.is_protocol(RuntimeCheckableFoo))
 static_assert(typing_extensions.is_protocol(RuntimeCheckableBar))
-static_assert(is_equivalent_to(RuntimeCheckableFoo, RuntimeCheckableBar))
+
+# TODO: should pass
+static_assert(is_equivalent_to(RuntimeCheckableFoo, RuntimeCheckableBar))  # error: [static-assert-error]

 # These should not error because the protocols are decorated with `@runtime_checkable`
 isinstance(object(), RuntimeCheckableFoo)
@@ -300,12 +304,10 @@ reveal_type(typing.Protocol is not typing_extensions.Protocol)  # revealed: bool

 ## Calls to protocol classes

-<!-- snapshot-diagnostics -->
-
 Neither `Protocol`, nor any protocol class, can be directly instantiated:

 ```py
-from typing_extensions import Protocol, reveal_type
+from typing import Protocol

 # error: [call-non-callable]
 reveal_type(Protocol())  # revealed: Unknown
@@ -313,7 +315,7 @@ reveal_type(Protocol())  # revealed: Unknown
 class MyProtocol(Protocol):
    x: int

-# error: [call-non-callable] "Cannot instantiate class `MyProtocol`"
+# error
 reveal_type(MyProtocol())  # revealed: MyProtocol
 ```

@@ -361,8 +363,25 @@ class Foo(Protocol):
    def method_member(self) -> bytes:
        return b"foo"

-# TODO: actually a frozenset (requires support for legacy generics)
-reveal_type(get_protocol_members(Foo))  # revealed: tuple[Literal["method_member"], Literal["x"], Literal["y"], Literal["z"]]
+# TODO: at runtime, `get_protocol_members` returns a `frozenset`,
+# but for now we might pretend it returns a `tuple`, as we support heterogeneous `tuple` types
+# but not yet generic `frozenset`s
+#
+# So this should either be
+#
+# `tuple[Literal["x"], Literal["y"], Literal["z"], Literal["method_member"]]`
+#
+# `frozenset[Literal["x", "y", "z", "method_member"]]`
+reveal_type(get_protocol_members(Foo))  # revealed: @Todo(specialized non-generic class)
+```
+
+Calling `get_protocol_members` on a non-protocol class raises an error at runtime:
+
+```py
+class NotAProtocol: ...
+
+# TODO: should emit `[invalid-protocol]` error, should reveal `Unknown`
+reveal_type(get_protocol_members(NotAProtocol))  # revealed: @Todo(specialized non-generic class)
 ```

 Certain special attributes and methods are not considered protocol members at runtime, and should
@@ -380,87 +399,8 @@ class Lumberjack(Protocol):
    def __init__(self, x: int) -> None:
        self.x = x

-# TODO: actually a frozenset
-reveal_type(get_protocol_members(Lumberjack))  # revealed: tuple[Literal["x"]]
-```
-
-A sub-protocol inherits and extends the members of its superclass protocol(s):
-
-```py
-class Bar(Protocol):
-    spam: str
-
-class Baz(Bar, Protocol):
-    ham: memoryview
-
-# TODO: actually a frozenset
-reveal_type(get_protocol_members(Baz))  # revealed: tuple[Literal["ham"], Literal["spam"]]
-
-class Baz2(Bar, Foo, Protocol): ...
-
-# TODO: actually a frozenset
-# revealed: tuple[Literal["method_member"], Literal["spam"], Literal["x"], Literal["y"], Literal["z"]]
-reveal_type(get_protocol_members(Baz2))
-```
-
-## Protocol members in statically known branches
-
-The list of protocol members does not include any members declared in branches that are statically
-known to be unreachable:
-
-```toml
-[environment]
-python-version = "3.9"
-```
-
-```py
-import sys
-from typing_extensions import Protocol, get_protocol_members
-
-class Foo(Protocol):
-    if sys.version_info >= (3, 10):
-        a: int
-        b = 42
-        def c(self) -> None: ...
-    else:
-        d: int
-        e = 56
-        def f(self) -> None: ...
-
-# TODO: actually a frozenset
-reveal_type(get_protocol_members(Foo))  # revealed: tuple[Literal["d"], Literal["e"], Literal["f"]]
-```
-
-## Invalid calls to `get_protocol_members()`
-
-<!-- snapshot-diagnostics -->
-
-Calling `get_protocol_members` on a non-protocol class raises an error at runtime:
-
-```toml
-[environment]
-python-version = "3.12"
-```
-
-```py
-from typing_extensions import Protocol, get_protocol_members
-
-class NotAProtocol: ...
-
-get_protocol_members(NotAProtocol)  # error: [invalid-argument-type]
-
-class AlsoNotAProtocol(NotAProtocol, object): ...
-
-get_protocol_members(AlsoNotAProtocol)  # error: [invalid-argument-type]
-```
-
-The original class object must be passed to the function; a specialised version of a generic version
-does not suffice:
-
-```py
-class GenericProtocol[T](Protocol): ...
-
-get_protocol_members(GenericProtocol[int])  # TODO: should emit a diagnostic here (https://github.com/astral-sh/ruff/issues/17549)
+# TODO: `tuple[Literal["x"]]` or `frozenset[Literal["x"]]`
+reveal_type(get_protocol_members(Lumberjack))  # revealed: @Todo(specialized non-generic class)
 ```

 ## Subtyping of protocols with attribute members
@@ -469,11 +409,6 @@ In the following example, the protocol class `HasX` defines an interface such th
 static type can be said to be a subtype of `HasX` if all inhabitants of that other type have a
 mutable `x` attribute of type `int`:

-```toml
-[environment]
-python-version = "3.12"
-```
-
 ```py
 from typing import Protocol
 from knot_extensions import static_assert, is_assignable_to, is_subtype_of
@@ -484,20 +419,21 @@ class HasX(Protocol):
 class Foo:
    x: int

-static_assert(is_subtype_of(Foo, HasX))
-static_assert(is_assignable_to(Foo, HasX))
+# TODO: these should pass
+static_assert(is_subtype_of(Foo, HasX))  # error: [static-assert-error]
+static_assert(is_assignable_to(Foo, HasX))  # error: [static-assert-error]

 class FooSub(Foo): ...

-static_assert(is_subtype_of(FooSub, HasX))
-static_assert(is_assignable_to(FooSub, HasX))
+# TODO: these should pass
+static_assert(is_subtype_of(FooSub, HasX))  # error: [static-assert-error]
+static_assert(is_assignable_to(FooSub, HasX))  # error: [static-assert-error]

 class Bar:
    x: str

-# TODO: these should pass
-static_assert(not is_subtype_of(Bar, HasX))  # error: [static-assert-error]
-static_assert(not is_assignable_to(Bar, HasX))  # error: [static-assert-error]
+static_assert(not is_subtype_of(Bar, HasX))
+static_assert(not is_assignable_to(Bar, HasX))

 class Baz:
    y: int
@@ -519,16 +455,14 @@ class A:
    def x(self) -> int:
        return 42

-# TODO: these should pass
-static_assert(not is_subtype_of(A, HasX))  # error: [static-assert-error]
-static_assert(not is_assignable_to(A, HasX))  # error: [static-assert-error]
+static_assert(not is_subtype_of(A, HasX))
+static_assert(not is_assignable_to(A, HasX))

 class B:
    x: Final = 42

-# TODO: these should pass
-static_assert(not is_subtype_of(A, HasX))  # error: [static-assert-error]
-static_assert(not is_assignable_to(A, HasX))  # error: [static-assert-error]
+static_assert(not is_subtype_of(A, HasX))
+static_assert(not is_assignable_to(A, HasX))

 class IntSub(int): ...

@@ -538,10 +472,8 @@ class C:
 # due to invariance, a type is only a subtype of `HasX`
 # if its `x` attribute is of type *exactly* `int`:
 # a subclass of `int` does not satisfy the interface
-#
-# TODO: these should pass
-static_assert(not is_subtype_of(C, HasX))  # error: [static-assert-error]
-static_assert(not is_assignable_to(C, HasX))  # error: [static-assert-error]
+static_assert(not is_subtype_of(C, HasX))
+static_assert(not is_assignable_to(C, HasX))
 ```

 All attributes on frozen dataclasses and namedtuples are immutable, so instances of these classes
@@ -555,23 +487,22 @@ from typing import NamedTuple
 class MutableDataclass:
    x: int

-static_assert(is_subtype_of(MutableDataclass, HasX))
-static_assert(is_assignable_to(MutableDataclass, HasX))
+# TODO: these should pass
+static_assert(is_subtype_of(MutableDataclass, HasX))  # error: [static-assert-error]
+static_assert(is_assignable_to(MutableDataclass, HasX))  # error: [static-assert-error]

@dataclass(frozen=True)
 class ImmutableDataclass:
    x: int

-# TODO: these should pass
-static_assert(not is_subtype_of(ImmutableDataclass, HasX))  # error: [static-assert-error]
-static_assert(not is_assignable_to(ImmutableDataclass, HasX))  # error: [static-assert-error]
+static_assert(not is_subtype_of(ImmutableDataclass, HasX))
+static_assert(not is_assignable_to(ImmutableDataclass, HasX))

 class NamedTupleWithX(NamedTuple):
    x: int

-# TODO: these should pass
-static_assert(not is_subtype_of(NamedTupleWithX, HasX))  # error: [static-assert-error]
-static_assert(not is_assignable_to(NamedTupleWithX, HasX))  # error: [static-assert-error]
+static_assert(not is_subtype_of(NamedTupleWithX, HasX))
+static_assert(not is_assignable_to(NamedTupleWithX, HasX))
 ```

 However, a type with a read-write property `x` *does* satisfy the `HasX` protocol. The `HasX`
@@ -590,8 +521,9 @@ class XProperty:
    def x(self, x: int) -> None:
        self._x = x**2

-static_assert(is_subtype_of(XProperty, HasX))
-static_assert(is_assignable_to(XProperty, HasX))
+# TODO: these should pass
+static_assert(is_subtype_of(XProperty, HasX))  # error: [static-assert-error]
+static_assert(is_assignable_to(XProperty, HasX))  # error: [static-assert-error]
 ```

 Attribute members on protocol classes are allowed to have default values, just like instance
@@ -616,61 +548,9 @@ def f(arg: HasXWithDefault):
    reveal_type(type(arg).x)  # revealed: int
 ```

-Assignments in a class body of a protocol -- of any kind -- are not permitted by red-knot unless the
-symbol being assigned to is also explicitly declared in the protocol's class body. Note that this is
-stricter validation of protocol members than many other type checkers currently apply (as of
-2025/04/21).
-
-The reason for this strict validation is that undeclared variables in the class body would lead to
-an ambiguous interface being declared by the protocol.
-
-```py
-from typing_extensions import TypeAlias, get_protocol_members
-
-class MyContext:
-    def __enter__(self) -> int:
-        return 42
-
-    def __exit__(self, *args) -> None: ...
-
-class LotsOfBindings(Protocol):
-    a: int
-    a = 42  # this is fine, since `a` is declared in the class body
-    b: int = 56  # this is also fine, by the same principle
-
-    type c = str  # this is very strange but I can't see a good reason to disallow it
-    d: TypeAlias = bytes  # same here
-
-    class Nested: ...  # also weird, but we should also probably allow it
-    class NestedProtocol(Protocol): ...  # same here...
-    e = 72  # TODO: this should error with `[invalid-protocol]` (`e` is not declared)
-
-    f, g = (1, 2)  # TODO: this should error with `[invalid-protocol]` (`f` and `g` are not declared)
-
-    h: int = (i := 3)  # TODO: this should error with `[invalid-protocol]` (`i` is not declared)
-
-    for j in range(42):  # TODO: this should error with `[invalid-protocol]` (`j` is not declared)
-        pass
-
-    with MyContext() as k:  # TODO: this should error with `[invalid-protocol]` (`k` is not declared)
-        pass
-
-    match object():
-        case l:  # TODO: this should error with `[invalid-protocol]` (`l` is not declared)
-            ...
-
-# TODO: actually a frozenset
-# revealed: tuple[Literal["Nested"], Literal["NestedProtocol"], Literal["a"], Literal["b"], Literal["c"], Literal["d"], Literal["e"], Literal["f"], Literal["g"], Literal["h"], Literal["i"], Literal["j"], Literal["k"], Literal["l"]]
-reveal_type(get_protocol_members(LotsOfBindings))
-```
-
 Attribute members are allowed to have assignments in methods on the protocol class, just like
-non-protocol classes. Unlike other classes, however, instance attributes that are not declared in
-the class body are disallowed. This is mandated by [the spec][spec_protocol_members]:
-
-> Additional attributes *only* defined in the body of a method by assignment via `self` are not
-> allowed. The rationale for this is that the protocol class implementation is often not shared by
-> subtypes, so the interface should not depend on the default implementation.
+non-protocol classes. Unlike other classes, however, *implicit* instance attributes -- those that
+are not declared in the class body -- are not allowed:

 ```py
 class Foo(Protocol):
@@ -679,33 +559,11 @@ class Foo(Protocol):

    def __init__(self) -> None:
        self.x = 42  # fine
-        self.a = 56  # TODO: should emit diagnostic
-        self.b: int = 128  # TODO: should emit diagnostic
+        self.a = 56  # error

    def non_init_method(self) -> None:
        self.y = 64  # fine
-        self.c = 72  # TODO: should emit diagnostic
-
-# Note: the list of members does not include `a`, `b` or `c`,
-# as none of these attributes is declared in the class body.
-#
-# TODO: actually a frozenset
-reveal_type(get_protocol_members(Foo))  # revealed: tuple[Literal["non_init_method"], Literal["x"], Literal["y"]]
-```
-
-If a member is declared in a superclass of a protocol class, it is fine for it to be assigned to in
-the sub-protocol class without a redeclaration:
-
-```py
-class Super(Protocol):
-    x: int
-
-class Sub(Super, Protocol):
-    x = 42  # no error here, since it's declared in the superclass
-
-# TODO: actually frozensets
-reveal_type(get_protocol_members(Super))  # revealed: tuple[Literal["x"]]
-reveal_type(get_protocol_members(Sub))  # revealed: tuple[Literal["x"]]
+        self.b = 72  # error
 ```

 If a protocol has 0 members, then all other types are assignable to it, and all fully static types
@@ -716,8 +574,9 @@ from typing import Protocol

 class UniversalSet(Protocol): ...

-static_assert(is_assignable_to(object, UniversalSet))
-static_assert(is_subtype_of(object, UniversalSet))
+# TODO: these should pass
+static_assert(is_assignable_to(object, UniversalSet))  # error: [static-assert-error]
+static_assert(is_subtype_of(object, UniversalSet))  # error: [static-assert-error]
 ```

 Which means that `UniversalSet` here is in fact an equivalent type to `object`:
@@ -725,7 +584,8 @@ Which means that `UniversalSet` here is in fact an equivalent type to `object`:
 ```py
 from knot_extensions import is_equivalent_to

-static_assert(is_equivalent_to(UniversalSet, object))
+# TODO: this should pass
+static_assert(is_equivalent_to(UniversalSet, object))  # error: [static-assert-error]
 ```

 `object` is a subtype of certain other protocols too. Since all fully static types (whether nominal
@@ -736,16 +596,17 @@ means that these protocols are also equivalent to `UniversalSet` and `object`:
 class SupportsStr(Protocol):
    def __str__(self) -> str: ...

-static_assert(is_equivalent_to(SupportsStr, UniversalSet))
-static_assert(is_equivalent_to(SupportsStr, object))
+# TODO: these should pass
+static_assert(is_equivalent_to(SupportsStr, UniversalSet))  # error: [static-assert-error]
+static_assert(is_equivalent_to(SupportsStr, object))  # error: [static-assert-error]

 class SupportsClass(Protocol):
-    @property
-    def __class__(self) -> type: ...
+    __class__: type

-static_assert(is_equivalent_to(SupportsClass, UniversalSet))
-static_assert(is_equivalent_to(SupportsClass, SupportsStr))
-static_assert(is_equivalent_to(SupportsClass, object))
+# TODO: these should pass
+static_assert(is_equivalent_to(SupportsClass, UniversalSet))  # error: [static-assert-error]
+static_assert(is_equivalent_to(SupportsClass, SupportsStr))  # error: [static-assert-error]
+static_assert(is_equivalent_to(SupportsClass, object))  # error: [static-assert-error]
 ```

 If a protocol contains members that are not defined on `object`, then that protocol will (like all
@@ -782,7 +643,8 @@ class HasX(Protocol):
 class AlsoHasX(Protocol):
    x: int

-static_assert(is_equivalent_to(HasX, AlsoHasX))
+# TODO: this should pass
+static_assert(is_equivalent_to(HasX, AlsoHasX))  # error: [static-assert-error]
 ```

 And unions containing equivalent protocols are recognised as equivalent, even when the order is not
@@ -798,7 +660,8 @@ class AlsoHasY(Protocol):
 class A: ...
 class B: ...

-static_assert(is_equivalent_to(A | HasX | B | HasY, B | AlsoHasY | AlsoHasX | A))
+# TODO: this should pass
+static_assert(is_equivalent_to(A | HasX | B | HasY, B | AlsoHasY | AlsoHasX | A))  # error: [static-assert-error]
 ```

 ## Intersections of protocols
@@ -876,9 +739,9 @@ from knot_extensions import is_subtype_of, is_assignable_to, static_assert, Type
 class HasX(Protocol):
    x: int

-# TODO: this should pass
+# TODO: these should pass
 static_assert(is_subtype_of(TypeOf[module], HasX))  # error: [static-assert-error]
-static_assert(is_assignable_to(TypeOf[module], HasX))
+static_assert(is_assignable_to(TypeOf[module], HasX))  # error: [static-assert-error]

 class ExplicitProtocolSubtype(HasX, Protocol):
    y: int
@@ -890,8 +753,9 @@ class ImplicitProtocolSubtype(Protocol):
    x: int
    y: str

-static_assert(is_subtype_of(ImplicitProtocolSubtype, HasX))
-static_assert(is_assignable_to(ImplicitProtocolSubtype, HasX))
+# TODO: these should pass
+static_assert(is_subtype_of(ImplicitProtocolSubtype, HasX))  # error: [static-assert-error]
+static_assert(is_assignable_to(ImplicitProtocolSubtype, HasX))  # error: [static-assert-error]

 class Meta(type):
    x: int
@@ -926,24 +790,23 @@ def f(obj: ClassVarXProto):
 class InstanceAttrX:
    x: int

-# TODO: these should pass
-static_assert(not is_assignable_to(InstanceAttrX, ClassVarXProto))  # error: [static-assert-error]
-static_assert(not is_subtype_of(InstanceAttrX, ClassVarXProto))  # error: [static-assert-error]
+static_assert(not is_assignable_to(InstanceAttrX, ClassVarXProto))
+static_assert(not is_subtype_of(InstanceAttrX, ClassVarXProto))

 class PropertyX:
    @property
    def x(self) -> int:
        return 42

-# TODO: these should pass
-static_assert(not is_assignable_to(PropertyX, ClassVarXProto))  # error: [static-assert-error]
-static_assert(not is_subtype_of(PropertyX, ClassVarXProto))  # error: [static-assert-error]
+static_assert(not is_assignable_to(PropertyX, ClassVarXProto))
+static_assert(not is_subtype_of(PropertyX, ClassVarXProto))

 class ClassVarX:
    x: ClassVar[int] = 42

-static_assert(is_assignable_to(ClassVarX, ClassVarXProto))
-static_assert(is_subtype_of(ClassVarX, ClassVarXProto))
+# TODO: these should pass
+static_assert(is_assignable_to(ClassVarX, ClassVarXProto))  # error: [static-assert-error]
+static_assert(is_subtype_of(ClassVarX, ClassVarXProto))  # error: [static-assert-error]
 ```

 This is mentioned by the
@@ -970,16 +833,18 @@ class HasXProperty(Protocol):
 class XAttr:
    x: int

-static_assert(is_subtype_of(XAttr, HasXProperty))
-static_assert(is_assignable_to(XAttr, HasXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XAttr, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XAttr, HasXProperty))  # error: [static-assert-error]

 class XReadProperty:
    @property
    def x(self) -> int:
        return 42

-static_assert(is_subtype_of(XReadProperty, HasXProperty))
-static_assert(is_assignable_to(XReadProperty, HasXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XReadProperty, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XReadProperty, HasXProperty))  # error: [static-assert-error]

 class XReadWriteProperty:
    @property
@@ -989,20 +854,22 @@ class XReadWriteProperty:
    @x.setter
    def x(self, val: int) -> None: ...

-static_assert(is_subtype_of(XReadWriteProperty, HasXProperty))
-static_assert(is_assignable_to(XReadWriteProperty, HasXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XReadWriteProperty, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XReadWriteProperty, HasXProperty))  # error: [static-assert-error]

 class XClassVar:
    x: ClassVar[int] = 42

-static_assert(is_subtype_of(XClassVar, HasXProperty))
-static_assert(is_assignable_to(XClassVar, HasXProperty))
+static_assert(is_subtype_of(XClassVar, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XClassVar, HasXProperty))  # error: [static-assert-error]

 class XFinal:
    x: Final = 42

-static_assert(is_subtype_of(XFinal, HasXProperty))
-static_assert(is_assignable_to(XFinal, HasXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XFinal, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XFinal, HasXProperty))  # error: [static-assert-error]
 ```

 A read-only property on a protocol, unlike a mutable attribute, is covariant: `XSub` in the below
@@ -1015,8 +882,9 @@ class MyInt(int): ...
 class XSub:
    x: MyInt

-static_assert(is_subtype_of(XSub, HasXProperty))
-static_assert(is_assignable_to(XSub, HasXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XSub, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XSub, HasXProperty))  # error: [static-assert-error]
 ```

 A read/write property on a protocol, where the getter returns the same type that the setter takes,
@@ -1032,17 +900,17 @@ class HasMutableXProperty(Protocol):
 class XAttr:
    x: int

-static_assert(is_subtype_of(XAttr, HasXProperty))
-static_assert(is_assignable_to(XAttr, HasXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XAttr, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XAttr, HasXProperty))  # error: [static-assert-error]

 class XReadProperty:
    @property
    def x(self) -> int:
        return 42

-# TODO: these should pass
-static_assert(not is_subtype_of(XReadProperty, HasXProperty))  # error: [static-assert-error]
-static_assert(not is_assignable_to(XReadProperty, HasXProperty))  # error: [static-assert-error]
+static_assert(not is_subtype_of(XReadProperty, HasXProperty))
+static_assert(not is_assignable_to(XReadProperty, HasXProperty))

 class XReadWriteProperty:
    @property
@@ -1052,15 +920,15 @@ class XReadWriteProperty:
    @x.setter
    def x(self, val: int) -> None: ...

-static_assert(is_subtype_of(XReadWriteProperty, HasXProperty))
-static_assert(is_assignable_to(XReadWriteProperty, HasXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XReadWriteProperty, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XReadWriteProperty, HasXProperty))  # error: [static-assert-error]

 class XSub:
    x: MyInt

-# TODO: should pass
-static_assert(not is_subtype_of(XSub, HasXProperty))  # error: [static-assert-error]
-static_assert(not is_assignable_to(XSub, HasXProperty))  # error: [static-assert-error]
+static_assert(not is_subtype_of(XSub, HasXProperty))
+static_assert(not is_assignable_to(XSub, HasXProperty))
 ```

 A protocol with a read/write property `x` is exactly equivalent to a protocol with a mutable
@@ -1072,13 +940,16 @@ from knot_extensions import is_equivalent_to
 class HasMutableXAttr(Protocol):
    x: int

-static_assert(is_equivalent_to(HasMutableXAttr, HasMutableXProperty))
+# TODO: this should pass
+static_assert(is_equivalent_to(HasMutableXAttr, HasMutableXProperty))  # error: [static-assert-error]

-static_assert(is_subtype_of(HasMutableXAttr, HasXProperty))
-static_assert(is_assignable_to(HasMutableXAttr, HasXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(HasMutableXAttr, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(HasMutableXAttr, HasXProperty))  # error: [static-assert-error]

-static_assert(is_subtype_of(HasMutableXProperty, HasXProperty))
-static_assert(is_assignable_to(HasMutableXProperty, HasXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(HasMutableXProperty, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(HasMutableXProperty, HasXProperty))  # error: [static-assert-error]
 ```

 A read/write property on a protocol, where the setter accepts a subtype of the type returned by the
@@ -1105,8 +976,9 @@ class HasAsymmetricXProperty(Protocol):
 class XAttr:
    x: int

-static_assert(is_subtype_of(XAttr, HasAsymmetricXProperty))
-static_assert(is_assignable_to(XAttr, HasAsymmetricXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XAttr, HasAsymmetricXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XAttr, HasAsymmetricXProperty))  # error: [static-assert-error]
 ```

 The end conclusion of this is that the getter-returned type of a property is always covariant and
@@ -1117,8 +989,9 @@ regular mutable attribute, where the implied getter-returned and setter-accepted
 class XAttrSub:
    x: MyInt

-static_assert(is_subtype_of(XAttrSub, HasAsymmetricXProperty))
-static_assert(is_assignable_to(XAttrSub, HasAsymmetricXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XAttrSub, HasAsymmetricXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XAttrSub, HasAsymmetricXProperty))  # error: [static-assert-error]

 class MyIntSub(MyInt):
    pass
@@ -1126,9 +999,8 @@ class MyIntSub(MyInt):
 class XAttrSubSub:
    x: MyIntSub

-# TODO: should pass
-static_assert(not is_subtype_of(XAttrSubSub, HasAsymmetricXProperty))  # error: [static-assert-error]
-static_assert(not is_assignable_to(XAttrSubSub, HasAsymmetricXProperty))  # error: [static-assert-error]
+static_assert(not is_subtype_of(XAttrSubSub, HasAsymmetricXProperty))
+static_assert(not is_assignable_to(XAttrSubSub, HasAsymmetricXProperty))
 ```

 An asymmetric property on a protocol can also be satisfied by an asymmetric property on a nominal
@@ -1144,8 +1016,9 @@ class XAsymmetricProperty:
    @x.setter
    def x(self, x: int) -> None: ...

-static_assert(is_subtype_of(XAsymmetricProperty, HasAsymmetricXProperty))
-static_assert(is_assignable_to(XAsymmetricProperty, HasAsymmetricXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XAsymmetricProperty, HasAsymmetricXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XAsymmetricProperty, HasAsymmetricXProperty))  # error: [static-assert-error]
 ```

 A custom descriptor attribute on the nominal class will also suffice:
@@ -1160,8 +1033,9 @@ class Descriptor:
 class XCustomDescriptor:
    x: Descriptor = Descriptor()

-static_assert(is_subtype_of(XCustomDescriptor, HasAsymmetricXProperty))
-static_assert(is_assignable_to(XCustomDescriptor, HasAsymmetricXProperty))
+# TODO: these should pass
+static_assert(is_subtype_of(XCustomDescriptor, HasAsymmetricXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(XCustomDescriptor, HasAsymmetricXProperty))  # error: [static-assert-error]
 ```

 Moreover, a read-only property on a protocol can be satisfied by a nominal class that defines a
@@ -1174,20 +1048,19 @@ class HasGetAttr:
    def __getattr__(self, attr: str) -> int:
        return 42

-static_assert(is_subtype_of(HasGetAttr, HasXProperty))
-static_assert(is_assignable_to(HasGetAttr, HasXProperty))
-
 # TODO: these should pass
-static_assert(not is_subtype_of(HasGetAttr, HasMutableXAttr))  # error: [static-assert-error]
-static_assert(not is_subtype_of(HasGetAttr, HasMutableXAttr))  # error: [static-assert-error]
+static_assert(is_subtype_of(HasGetAttr, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(HasGetAttr, HasXProperty))  # error: [static-assert-error]
+
+static_assert(not is_subtype_of(HasGetAttr, HasMutableXAttr))
+static_assert(not is_subtype_of(HasGetAttr, HasMutableXAttr))

 class HasGetAttrWithUnsuitableReturn:
    def __getattr__(self, attr: str) -> tuple[int, int]:
        return (1, 2)

-# TODO: these should pass
-static_assert(not is_subtype_of(HasGetAttrWithUnsuitableReturn, HasXProperty))  # error: [static-assert-error]
-static_assert(not is_assignable_to(HasGetAttrWithUnsuitableReturn, HasXProperty))  # error: [static-assert-error]
+static_assert(not is_subtype_of(HasGetAttrWithUnsuitableReturn, HasXProperty))
+static_assert(not is_assignable_to(HasGetAttrWithUnsuitableReturn, HasXProperty))

 class HasGetAttrAndSetAttr:
    def __getattr__(self, attr: str) -> MyInt:
@@ -1195,35 +1068,32 @@ class HasGetAttrAndSetAttr:

    def __setattr__(self, attr: str, value: int) -> None: ...

-static_assert(is_subtype_of(HasGetAttrAndSetAttr, HasXProperty))
-static_assert(is_assignable_to(HasGetAttrAndSetAttr, HasXProperty))
-
 # TODO: these should pass
+static_assert(is_subtype_of(HasGetAttrAndSetAttr, HasXProperty))  # error: [static-assert-error]
+static_assert(is_assignable_to(HasGetAttrAndSetAttr, HasXProperty))  # error: [static-assert-error]
 static_assert(is_subtype_of(HasGetAttrAndSetAttr, XAsymmetricProperty))  # error: [static-assert-error]
 static_assert(is_assignable_to(HasGetAttrAndSetAttr, XAsymmetricProperty))  # error: [static-assert-error]
 ```

 ## Narrowing of protocols

-<!-- snapshot-diagnostics -->
-
 By default, a protocol class cannot be used as the second argument to `isinstance()` or
 `issubclass()`, and a type checker must emit an error on such calls. However, we still narrow the
 type inside these branches (this matches the behaviour of other type checkers):

 ```py
-from typing_extensions import Protocol, reveal_type
+from typing import Protocol

 class HasX(Protocol):
    x: int

 def f(arg: object, arg2: type):
-    if isinstance(arg, HasX):  # error: [invalid-argument-type]
+    if isinstance(arg, HasX):  # error
        reveal_type(arg)  # revealed: HasX
    else:
        reveal_type(arg)  # revealed: ~HasX

-    if issubclass(arg2, HasX):  # error: [invalid-argument-type]
+    if issubclass(arg2, HasX):  # error
        reveal_type(arg2)  # revealed: type[HasX]
    else:
        reveal_type(arg2)  # revealed: type & ~type[HasX]
@@ -1258,10 +1128,10 @@ class OnlyMethodMembers(Protocol):
    def method(self) -> None: ...

 def f(arg1: type, arg2: type):
-    if issubclass(arg1, RuntimeCheckableHasX):  # TODO: should emit an error here (has non-method members)
-        reveal_type(arg1)  # revealed: type[RuntimeCheckableHasX]
+    if issubclass(arg1, OnlyMethodMembers):  # error
+        reveal_type(arg1)  # revealed: type[OnlyMethodMembers]
    else:
-        reveal_type(arg1)  # revealed: type & ~type[RuntimeCheckableHasX]
+        reveal_type(arg1)  # revealed: type & ~type[OnlyMethodMembers]

    if issubclass(arg2, OnlyMethodMembers):  # no error!
        reveal_type(arg2)  # revealed: type[OnlyMethodMembers]
@@ -1269,143 +1139,6 @@ def f(arg1: type, arg2: type):
        reveal_type(arg2)  # revealed: type & ~type[OnlyMethodMembers]
 ```

-## Truthiness of protocol instance
-
-An instance of a protocol type generally has ambiguous truthiness:
-
-```py
-from typing import Protocol
-
-class Foo(Protocol):
-    x: int
-
-def f(foo: Foo):
-    reveal_type(bool(foo))  # revealed: bool
-```
-
-But this is not the case if the protocol has a `__bool__` method member that returns `Literal[True]`
-or `Literal[False]`:
-
-```py
-from typing import Literal
-
-class Truthy(Protocol):
-    def __bool__(self) -> Literal[True]: ...
-
-class FalsyFoo(Foo, Protocol):
-    def __bool__(self) -> Literal[False]: ...
-
-class FalsyFooSubclass(FalsyFoo, Protocol):
-    y: str
-
-def g(a: Truthy, b: FalsyFoo, c: FalsyFooSubclass):
-    # TODO should be `Literal[True]
-    reveal_type(bool(a))  # revealed: bool
-    # TODO should be `Literal[False]
-    reveal_type(bool(b))  # revealed: bool
-    # TODO should be `Literal[False]
-    reveal_type(bool(c))  # revealed: bool
-```
-
-It is not sufficient for a protocol to have a callable `__bool__` instance member that returns
-`Literal[True]` for it to be considered always truthy. Dunder methods are looked up on the class
-rather than the instance. If a protocol `X` has an instance-attribute `__bool__` member, it is
-unknowable whether that attribute can be accessed on the type of an object that satisfies `X`'s
-interface:
-
-```py
-from typing import Callable
-
-class InstanceAttrBool(Protocol):
-    __bool__: Callable[[], Literal[True]]
-
-def h(obj: InstanceAttrBool):
-    reveal_type(bool(obj))  # revealed: bool
-```
-
-## Fully static protocols; gradual protocols
-
-A protocol is only fully static if all of its members are fully static:
-
-```py
-from typing import Protocol, Any
-from knot_extensions import is_fully_static, static_assert
-
-class FullyStatic(Protocol):
-    x: int
-
-class NotFullyStatic(Protocol):
-    x: Any
-
-static_assert(is_fully_static(FullyStatic))
-
-# TODO: should pass
-static_assert(not is_fully_static(NotFullyStatic))  # error: [static-assert-error]
-```
-
-Non-fully-static protocols do not participate in subtyping, only assignability:
-
-```py
-from knot_extensions import is_subtype_of, is_assignable_to
-
-class NominalWithX:
-    x: int = 42
-
-static_assert(is_assignable_to(NominalWithX, FullyStatic))
-static_assert(is_assignable_to(NominalWithX, NotFullyStatic))
-static_assert(is_subtype_of(NominalWithX, FullyStatic))
-
-# TODO: this should pass
-static_assert(not is_subtype_of(NominalWithX, NotFullyStatic))  # error: [static-assert-error]
-```
-
-Empty protocols are fully static; this follows from the fact that an empty protocol is equivalent to
-the nominal type `object` (as described above):
-
-```py
-class Empty(Protocol): ...
-
-static_assert(is_fully_static(Empty))
-```
-
-A method member is only considered fully static if all its parameter annotations and its return
-annotation are fully static:
-
-```py
-class FullyStaticMethodMember(Protocol):
-    def method(self, x: int) -> str: ...
-
-class DynamicParameter(Protocol):
-    def method(self, x: Any) -> str: ...
-
-class DynamicReturn(Protocol):
-    def method(self, x: int) -> Any: ...
-
-static_assert(is_fully_static(FullyStaticMethodMember))
-
-# TODO: these should pass
-static_assert(not is_fully_static(DynamicParameter))  # error: [static-assert-error]
-static_assert(not is_fully_static(DynamicReturn))  # error: [static-assert-error]
-```
-
-The [typing spec][spec_protocol_members] states:
-
-> If any parameters of a protocol method are not annotated, then their types are assumed to be `Any`
-
-Thus, a partially unannotated method member can also not be considered to be fully static:
-
-```py
-class NoParameterAnnotation(Protocol):
-    def method(self, x) -> str: ...
-
-class NoReturnAnnotation(Protocol):
-    def method(self, x: int): ...
-
-# TODO: these should pass
-static_assert(not is_fully_static(NoParameterAnnotation))  # error: [static-assert-error]
-static_assert(not is_fully_static(NoReturnAnnotation))  # error: [static-assert-error]
-```
-
 ## `typing.SupportsIndex` and `typing.Sized`

 `typing.SupportsIndex` is already somewhat supported through some special-casing in red-knot.
@@ -1434,10 +1167,10 @@ def _(some_list: list, some_tuple: tuple[int, str], some_sized: Sized):

 Add tests for:

+- Assignments without declarations in protocol class bodies. And various weird ways of creating
+    attributes in a class body or instance method. [Example mypy tests][mypy_weird_protocols].
 - More tests for protocols inside `type[]`. [Spec reference][protocols_inside_type_spec].
- Protocols with instance-method members, including:
-    - Protocols with methods that have parameters or the return type unannotated
-    - Protocols with methods that have parameters or the return type annotated with `Any`
+- Protocols with instance-method members
 - Protocols with `@classmethod` and `@staticmethod`
 - Assignability of non-instance types to protocols with instance-method members (e.g. a
    class-literal type can be a subtype of `Sized` if its metaclass has a `__len__` method)
@@ -1451,13 +1184,16 @@ Add tests for:
 - Protocols with instance attributes annotated with `Callable` (can a nominal type with a method
    satisfy that protocol, and if so in what cases?)
 - Protocols decorated with `@final`
+- Protocols with attribute members annotated with `Any`
+- Protocols with methods that have parameters or the return type unannotated
+- Protocols with methods that have parameters or the return type annotated with `Any`
 - Equivalence and subtyping between `Callable` types and protocols that define `__call__`

 [mypy_protocol_docs]: https://mypy.readthedocs.io/en/stable/protocols.html#protocols-and-structural-subtyping
 [mypy_protocol_tests]: https://github.com/python/mypy/blob/master/test-data/unit/check-protocols.test
+[mypy_weird_protocols]: https://github.com/python/mypy/blob/a3ce6d5307e99a1b6c181eaa7c5cf134c53b7d8b/test-data/unit/check-protocols.test#L2131-L2132
 [protocol conformance tests]: https://github.com/python/typing/tree/main/conformance/tests
 [protocols_inside_type_spec]: https://typing.python.org/en/latest/spec/protocol.html#type-and-class-objects-vs-protocols
 [recursive_protocols_spec]: https://typing.python.org/en/latest/spec/protocol.html#recursive-protocols
 [self_types_protocols_spec]: https://typing.python.org/en/latest/spec/protocol.html#self-types-in-protocols
-[spec_protocol_members]: https://typing.python.org/en/latest/spec/protocol.html#protocol-members
 [typing_spec_protocols]: https://typing.python.org/en/latest/spec/protocol.html
--- a/crates/red_knot_python_semantic/resources/mdtest/scopes/builtin.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/scopes/builtin.md
@@ -13,7 +13,7 @@ if returns_bool():
    chr: int = 1

 def f():
-    reveal_type(chr)  # revealed: int | (def chr(i: SupportsIndex, /) -> str)
+    reveal_type(chr)  # revealed: int | (def chr(i: int | SupportsIndex, /) -> str)
 ```

 ## Conditionally global or builtin, with annotation
@@ -28,5 +28,5 @@ if returns_bool():
    chr: int = 1

 def f():
-    reveal_type(chr)  # revealed: int | (def chr(i: SupportsIndex, /) -> str)
+    reveal_type(chr)  # revealed: int | (def chr(i: int | SupportsIndex, /) -> str)
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/scopes/eager.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/scopes/eager.md
@@ -404,7 +404,7 @@ x = int
 class C:
    var: ClassVar[x]

-reveal_type(C.var)  # revealed: str
+reveal_type(C.var)  # revealed: Unknown | str

 x = str
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/scopes/global.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/scopes/global.md
@@ -1,177 +0,0 @@
-# `global` references
-
-## Implicit global in function
-
-A name reference to a never-defined symbol in a function is implicitly a global lookup.
-
-```py
-x = 1
-
-def f():
-    reveal_type(x)  # revealed: Unknown | Literal[1]
-```
-
-## Explicit global in function
-
-```py
-x = 1
-
-def f():
-    global x
-    reveal_type(x)  # revealed: Unknown | Literal[1]
-```
-
-## Unassignable type in function
-
-```py
-x: int = 1
-
-def f():
-    y: int = 1
-    # error: [invalid-assignment] "Object of type `Literal[""]` is not assignable to `int`"
-    y = ""
-
-    global x
-    # TODO: error: [invalid-assignment] "Object of type `Literal[""]` is not assignable to `int`"
-    x = ""
-```
-
-## Nested intervening scope
-
-A `global` statement causes lookup to skip any bindings in intervening scopes:
-
-```py
-x: int = 1
-
-def outer():
-    x: str = ""
-
-    def inner():
-        global x
-        # TODO: revealed: int
-        reveal_type(x)  # revealed: str
-```
-
-## Narrowing
-
-An assignment following a `global` statement should narrow the type in the local scope after the
-assignment.
-
-```py
-x: int | None
-
-def f():
-    global x
-    x = 1
-    reveal_type(x)  # revealed: Literal[1]
-```
-
-## `nonlocal` and `global`
-
-A binding cannot be both `nonlocal` and `global`. This should emit a semantic syntax error. CPython
-marks the `nonlocal` line, while `mypy`, `pyright`, and `ruff` (`PLE0115`) mark the `global` line.
-
-```py
-x = 1
-
-def f():
-    x = 1
-    def g() -> None:
-        nonlocal x
-        global x  # TODO: error: [invalid-syntax] "name 'x' is nonlocal and global"
-        x = None
-```
-
-## Global declaration after `global` statement
-
-```py
-def f():
-    global x
-    # TODO this should also not be an error
-    y = x  # error: [unresolved-reference] "Name `x` used when not defined"
-    x = 1  # No error.
-
-x = 2
-```
-
-## Semantic syntax errors
-
-Using a name prior to its `global` declaration in the same scope is a syntax error.
-
-```py
-x = 1
-
-def f():
-    print(x)  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    print(x)
-
-def f():
-    global x
-    print(x)  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    print(x)
-
-def f():
-    print(x)  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    print(x)
-
-def f():
-    global x, y
-    print(x)  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    print(x)
-
-def f():
-    x = 1  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    x = 1
-
-def f():
-    global x
-    x = 1  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    x = 1
-
-def f():
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    del x
-
-def f():
-    global x, y
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    del x
-
-def f():
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    del x
-
-def f():
-    global x
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    del x
-
-def f():
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    del x
-
-def f():
-    global x, y
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    del x
-
-def f():
-    print(f"{x=}")  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-
-# still an error in module scope
-x = None  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-global x
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/scopes/nonlocal.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/scopes/nonlocal.md
@@ -43,3 +43,14 @@ def f():
        def h():
            reveal_type(x)  # revealed: Unknown | Literal[1]
 ```
+
+## Implicit global in function
+
+A name reference to a never-defined symbol in a function is implicitly a global lookup.
+
+```py
+x = 1
+
+def f():
+    reveal_type(x)  # revealed: Unknown | Literal[1]
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/shadowing/class.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/shadowing/class.md
@@ -5,7 +5,7 @@
 ```py
 class C: ...

-C = 1  # error: "Implicit shadowing of class `C`"
+C = 1  # error: "Implicit shadowing of class `C`; annotate to make it explicit if this is intentional"
 ```

 ## Explicit
--- a/crates/red_knot_python_semantic/resources/mdtest/shadowing/function.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/shadowing/function.md
@@ -15,7 +15,7 @@ def f(x: str):
 ```py
 def f(): ...

-f = 1  # error: "Implicit shadowing of function `f`"
+f = 1  # error: "Implicit shadowing of function `f`; annotate to make it explicit if this is intentional"
 ```

 ## Explicit shadowing
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Data_descriptors_-_Invalid_`set`_method_signature.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Data_descriptors_-_Invalid_`set`_method_signature.snap
@@ -28,12 +28,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/attrib
 # Diagnostics

 ```
-error: lint:invalid-assignment: Invalid assignment to data descriptor attribute `attr` on type `C` with custom `__set__` method
+error: lint:invalid-assignment
  --> /src/mdtest_snippet.py:11:1
   |
 10 | # TODO: ideally, we would mention why this is an invalid assignment (wrong number of arguments for `__set__`)
 11 | instance.attr = 1  # error: [invalid-assignment]
-   | ^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^ Invalid assignment to data descriptor attribute `attr` on type `C` with custom `__set__` method
   |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Data_descriptors_-_Invalid_argument_type.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Data_descriptors_-_Invalid_argument_type.snap
@@ -29,12 +29,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/attrib
 # Diagnostics

 ```
-error: lint:invalid-assignment: Invalid assignment to data descriptor attribute `attr` on type `C` with custom `__set__` method
+error: lint:invalid-assignment
  --> /src/mdtest_snippet.py:12:1
   |
 11 | # TODO: ideally, we would mention why this is an invalid assignment (wrong argument type for `value` parameter)
 12 | instance.attr = "wrong"  # error: [invalid-assignment]
-   | ^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^ Invalid assignment to data descriptor attribute `attr` on type `C` with custom `__set__` method
   |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Instance_attributes_with_class-level_defaults.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Instance_attributes_with_class-level_defaults.snap
@@ -26,13 +26,13 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/attrib
 # Diagnostics

 ```
-error: lint:invalid-assignment: Object of type `Literal["wrong"]` is not assignable to attribute `attr` of type `int`
+error: lint:invalid-assignment
 --> /src/mdtest_snippet.py:6:1
  |
 4 | instance = C()
 5 | instance.attr = 1  # fine
 6 | instance.attr = "wrong"  # error: [invalid-assignment]
-  | ^^^^^^^^^^^^^
+  | ^^^^^^^^^^^^^ Object of type `Literal["wrong"]` is not assignable to attribute `attr` of type `int`
 7 |
 8 | C.attr = 1  # fine
  |
@@ -40,12 +40,12 @@ error: lint:invalid-assignment: Object of type `Literal["wrong"]` is not assigna
 ```

 ```
-error: lint:invalid-assignment: Object of type `Literal["wrong"]` is not assignable to attribute `attr` of type `int`
+error: lint:invalid-assignment
 --> /src/mdtest_snippet.py:9:1
  |
 8 | C.attr = 1  # fine
 9 | C.attr = "wrong"  # error: [invalid-assignment]
-  | ^^^^^^
+  | ^^^^^^ Object of type `Literal["wrong"]` is not assignable to attribute `attr` of type `int`
  |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Possibly-unbound_attributes.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Possibly-unbound_attributes.snap
@@ -26,13 +26,13 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/attrib
 # Diagnostics

 ```
-warning: lint:possibly-unbound-attribute: Attribute `attr` on type `Literal[C]` is possibly unbound
+warning: lint:possibly-unbound-attribute
 --> /src/mdtest_snippet.py:6:5
  |
 4 |             attr: int = 0
 5 |
 6 |     C.attr = 1  # error: [possibly-unbound-attribute]
-  |     ^^^^^^
+  |     ^^^^^^ Attribute `attr` on type `Literal[C]` is possibly unbound
 7 |
 8 |     instance = C()
  |
@@ -40,12 +40,12 @@ warning: lint:possibly-unbound-attribute: Attribute `attr` on type `Literal[C]`
 ```

 ```
-warning: lint:possibly-unbound-attribute: Attribute `attr` on type `C` is possibly unbound
+warning: lint:possibly-unbound-attribute
 --> /src/mdtest_snippet.py:9:5
  |
 8 |     instance = C()
 9 |     instance.attr = 1  # error: [possibly-unbound-attribute]
-  |     ^^^^^^^^^^^^^
+  |     ^^^^^^^^^^^^^ Attribute `attr` on type `C` is possibly unbound
  |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Pure_instance_attributes.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Pure_instance_attributes.snap
@@ -26,13 +26,13 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/attrib
 # Diagnostics

 ```
-error: lint:invalid-assignment: Object of type `Literal["wrong"]` is not assignable to attribute `attr` of type `int`
+error: lint:invalid-assignment
 --> /src/mdtest_snippet.py:7:1
  |
 5 | instance = C()
 6 | instance.attr = 1  # fine
 7 | instance.attr = "wrong"  # error: [invalid-assignment]
-  | ^^^^^^^^^^^^^
+  | ^^^^^^^^^^^^^ Object of type `Literal["wrong"]` is not assignable to attribute `attr` of type `int`
 8 |
 9 | C.attr = 1  # error: [invalid-attribute-access]
  |
@@ -40,13 +40,13 @@ error: lint:invalid-assignment: Object of type `Literal["wrong"]` is not assigna
 ```

 ```
-error: lint:invalid-attribute-access: Cannot assign to instance attribute `attr` from the class object `Literal[C]`
+error: lint:invalid-attribute-access
 --> /src/mdtest_snippet.py:9:1
  |
 7 | instance.attr = "wrong"  # error: [invalid-assignment]
 8 |
 9 | C.attr = 1  # error: [invalid-attribute-access]
-  | ^^^^^^
+  | ^^^^^^ Cannot assign to instance attribute `attr` from the class object `Literal[C]`
  |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Setting_attributes_on_union_types.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Setting_attributes_on_union_types.snap
@@ -37,12 +37,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/attrib
 # Diagnostics

 ```
-error: lint:invalid-assignment: Object of type `Literal[1]` is not assignable to attribute `attr` on type `Literal[C1, C1]`
+error: lint:invalid-assignment
  --> /src/mdtest_snippet.py:11:5
   |
 10 |     # TODO: The error message here could be improved to explain why the assignment fails.
 11 |     C1.attr = 1  # error: [invalid-assignment]
-   |     ^^^^^^^
+   |     ^^^^^^^ Object of type `Literal[1]` is not assignable to attribute `attr` on type `Literal[C1, C1]`
 12 |
 13 |     class C2:
   |
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Unknown_attributes.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_Unknown_attributes.snap
@@ -23,13 +23,13 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/attrib
 # Diagnostics

 ```
-error: lint:unresolved-attribute: Unresolved attribute `non_existent` on type `Literal[C]`.
+error: lint:unresolved-attribute
 --> /src/mdtest_snippet.py:3:1
  |
 1 | class C: ...
 2 |
 3 | C.non_existent = 1  # error: [unresolved-attribute]
-  | ^^^^^^^^^^^^^^
+  | ^^^^^^^^^^^^^^ Unresolved attribute `non_existent` on type `Literal[C]`.
 4 |
 5 | instance = C()
  |
@@ -37,12 +37,12 @@ error: lint:unresolved-attribute: Unresolved attribute `non_existent` on type `L
 ```

 ```
-error: lint:unresolved-attribute: Unresolved attribute `non_existent` on type `C`.
+error: lint:unresolved-attribute
 --> /src/mdtest_snippet.py:6:1
  |
 5 | instance = C()
 6 | instance.non_existent = 1  # error: [unresolved-attribute]
-  | ^^^^^^^^^^^^^^^^^^^^^
+  | ^^^^^^^^^^^^^^^^^^^^^ Unresolved attribute `non_existent` on type `C`.
  |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_`ClassVar`s.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/attribute_assignment.md_-_Attribute_assignment_-_`ClassVar`s.snap
@@ -27,12 +27,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/attrib
 # Diagnostics

 ```
-error: lint:invalid-assignment: Object of type `Literal["wrong"]` is not assignable to attribute `attr` of type `int`
+error: lint:invalid-assignment
 --> /src/mdtest_snippet.py:7:1
  |
 6 | C.attr = 1  # fine
 7 | C.attr = "wrong"  # error: [invalid-assignment]
-  | ^^^^^^
+  | ^^^^^^ Object of type `Literal["wrong"]` is not assignable to attribute `attr` of type `int`
 8 |
 9 | instance = C()
  |
@@ -40,12 +40,12 @@ error: lint:invalid-assignment: Object of type `Literal["wrong"]` is not assigna
 ```

 ```
-error: lint:invalid-attribute-access: Cannot assign to ClassVar `attr` from an instance of type `C`
+error: lint:invalid-attribute-access
  --> /src/mdtest_snippet.py:10:1
   |
 9 | instance = C()
 10 | instance.attr = 1  # error: [invalid-attribute-access]
-   | ^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^ Cannot assign to ClassVar `attr` from an instance of type `C`
   |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_module_import.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_module_import.snap
@@ -18,11 +18,11 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/import/basic.md
 # Diagnostics

 ```
-error: lint:unresolved-import: Cannot resolve import `zqzqzqzqzqzqzq`
+error: lint:unresolved-import
 --> /src/mdtest_snippet.py:1:8
  |
 1 | import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve import `zqzqzqzqzqzqzq`"
-  |        ^^^^^^^^^^^^^^
+  |        ^^^^^^^^^^^^^^ Cannot resolve import `zqzqzqzqzqzqzq`
  |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_submodule_imports.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_submodule_imports.snap
@@ -27,12 +27,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/import/basic.md
 # Diagnostics

 ```
-error: lint:unresolved-import: Cannot resolve import `a.foo`
+error: lint:unresolved-import
 --> /src/mdtest_snippet.py:2:8
  |
 1 | # Topmost component resolvable, submodule not resolvable:
 2 | import a.foo  # error: [unresolved-import] "Cannot resolve import `a.foo`"
-  |        ^^^^^
+  |        ^^^^^ Cannot resolve import `a.foo`
 3 |
 4 | # Topmost component unresolvable:
  |
@@ -40,12 +40,12 @@ error: lint:unresolved-import: Cannot resolve import `a.foo`
 ```

 ```
-error: lint:unresolved-import: Cannot resolve import `b.foo`
+error: lint:unresolved-import
 --> /src/mdtest_snippet.py:5:8
  |
 4 | # Topmost component unresolvable:
 5 | import b.foo  # error: [unresolved-import] "Cannot resolve import `b.foo`"
-  |        ^^^^^
+  |        ^^^^^ Cannot resolve import `b.foo`
  |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Bad_`getitem`_method.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Bad_`getitem`_method.snap
@@ -28,12 +28,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Iterable` is not iterable because it has no `__iter__` method and its `__getitem__` method has an incorrect signature for the old-style iteration protocol (expected a signature at least as permissive as `def __getitem__(self, key: int): ...`)
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:10:10
   |
 9 | # error: [not-iterable]
 10 | for x in Iterable():
-   |          ^^^^^^^^^^
+   |          ^^^^^^^^^^ Object of type `Iterable` is not iterable because it has no `__iter__` method and its `__getitem__` method has an incorrect signature for the old-style iteration protocol (expected a signature at least as permissive as `def __getitem__(self, key: int): ...`)
 11 |     reveal_type(x)  # revealed: int
   |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Invalid_iterable.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Invalid_iterable.snap
@@ -20,12 +20,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Literal[123]` is not iterable because it doesn't have an `__iter__` method or a `__getitem__` method
+error: lint:not-iterable
 --> /src/mdtest_snippet.py:2:10
  |
 1 | nonsense = 123
 2 | for x in nonsense:  # error: [not-iterable]
-  |          ^^^^^^^^
+  |          ^^^^^^^^ Object of type `Literal[123]` is not iterable because it doesn't have an `__iter__` method or a `__getitem__` method
 3 |     pass
  |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_New_over_old_style_iteration_protocol.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_New_over_old_style_iteration_protocol.snap
@@ -24,13 +24,13 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `NotIterable` is not iterable because its `__iter__` attribute has type `None`, which is not callable
+error: lint:not-iterable
 --> /src/mdtest_snippet.py:6:10
  |
 4 |     __iter__: None = None
 5 |
 6 | for x in NotIterable():  # error: [not-iterable]
-  |          ^^^^^^^^^^^^^
+  |          ^^^^^^^^^^^^^ Object of type `NotIterable` is not iterable because its `__iter__` attribute has type `None`, which is not callable
 7 |     pass
  |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_No_`iter`_method_and_`getitem`_is_not_callable.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_No_`iter`_method_and_`getitem`_is_not_callable.snap
@@ -25,12 +25,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Bad` is not iterable because it has no `__iter__` method and its `__getitem__` attribute has type `None`, which is not callable
+error: lint:not-iterable
 --> /src/mdtest_snippet.py:7:10
  |
 6 | # error: [not-iterable]
 7 | for x in Bad():
-  |          ^^^^^
+  |          ^^^^^ Object of type `Bad` is not iterable because it has no `__iter__` method and its `__getitem__` attribute has type `None`, which is not callable
 8 |     reveal_type(x)  # revealed: Unknown
  |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly-not-callable_`getitem`_method.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly-not-callable_`getitem`_method.snap
@@ -46,12 +46,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Iterable1` may not be iterable because it has no `__iter__` method and its `__getitem__` attribute (with type `CustomCallable`) may not be callable
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:22:14
   |
 21 |     # error: [not-iterable]
 22 |     for x in Iterable1():
-   |              ^^^^^^^^^^^
+   |              ^^^^^^^^^^^ Object of type `Iterable1` may not be iterable because it has no `__iter__` method and its `__getitem__` attribute (with type `CustomCallable`) may not be callable
 23 |         # TODO... `int` might be ideal here?
 24 |         reveal_type(x)  # revealed: int | Unknown
   |
@@ -73,12 +73,12 @@ info: revealed-type: Revealed type
 ```

 ```
-error: lint:not-iterable: Object of type `Iterable2` may not be iterable because it has no `__iter__` method and its `__getitem__` attribute (with type `(bound method Iterable2.__getitem__(key: int) -> int) | None`) may not be callable
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:27:14
   |
 26 |     # error: [not-iterable]
 27 |     for y in Iterable2():
-   |              ^^^^^^^^^^^
+   |              ^^^^^^^^^^^ Object of type `Iterable2` may not be iterable because it has no `__iter__` method and its `__getitem__` attribute (with type `(bound method Iterable2.__getitem__(key: int) -> int) | None`) may not be callable
 28 |         # TODO... `int` might be ideal here?
 29 |         reveal_type(y)  # revealed: int | Unknown
   |
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_invalid_`getitem`_methods.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_invalid_`getitem`_methods.snap
@@ -43,12 +43,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Iterable1` may not be iterable because it has no `__iter__` method and its `__getitem__` attribute (with type `(bound method Iterable1.__getitem__(item: int) -> str) | None`) may not be callable
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:20:14
   |
 19 |     # error: [not-iterable]
 20 |     for x in Iterable1():
-   |              ^^^^^^^^^^^
+   |              ^^^^^^^^^^^ Object of type `Iterable1` may not be iterable because it has no `__iter__` method and its `__getitem__` attribute (with type `(bound method Iterable1.__getitem__(item: int) -> str) | None`) may not be callable
 21 |         # TODO: `str` might be better
 22 |         reveal_type(x)  # revealed: str | Unknown
   |
@@ -70,12 +70,12 @@ info: revealed-type: Revealed type
 ```

 ```
-error: lint:not-iterable: Object of type `Iterable2` may not be iterable because it has no `__iter__` method and its `__getitem__` method (with type `(bound method Iterable2.__getitem__(item: int) -> str) | (bound method Iterable2.__getitem__(item: str) -> int)`) may have an incorrect signature for the old-style iteration protocol (expected a signature at least as permissive as `def __getitem__(self, key: int): ...`)
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:25:14
   |
 24 |     # error: [not-iterable]
 25 |     for y in Iterable2():
-   |              ^^^^^^^^^^^
+   |              ^^^^^^^^^^^ Object of type `Iterable2` may not be iterable because it has no `__iter__` method and its `__getitem__` method (with type `(bound method Iterable2.__getitem__(item: int) -> str) | (bound method Iterable2.__getitem__(item: str) -> int)`) may have an incorrect signature for the old-style iteration protocol (expected a signature at least as permissive as `def __getitem__(self, key: int): ...`)
 26 |         reveal_type(y)  # revealed: str | int
   |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_invalid_`iter`_methods.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_invalid_`iter`_methods.snap
@@ -47,12 +47,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Iterable1` may not be iterable because its `__iter__` method (with type `(bound method Iterable1.__iter__() -> Iterator) | (bound method Iterable1.__iter__(invalid_extra_arg) -> Iterator)`) may have an invalid signature (expected `def __iter__(self): ...`)
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:17:14
   |
 16 |     # error: [not-iterable]
 17 |     for x in Iterable1():
-   |              ^^^^^^^^^^^
+   |              ^^^^^^^^^^^ Object of type `Iterable1` may not be iterable because its `__iter__` method (with type `(bound method Iterable1.__iter__() -> Iterator) | (bound method Iterable1.__iter__(invalid_extra_arg) -> Iterator)`) may have an invalid signature (expected `def __iter__(self): ...`)
 18 |         reveal_type(x)  # revealed: int
   |

@@ -73,12 +73,12 @@ info: revealed-type: Revealed type
 ```

 ```
-error: lint:not-iterable: Object of type `Iterable2` may not be iterable because its `__iter__` attribute (with type `(bound method Iterable2.__iter__() -> Iterator) | None`) may not be callable
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:28:14
   |
 27 |     # error: [not-iterable]
 28 |     for x in Iterable2():
-   |              ^^^^^^^^^^^
+   |              ^^^^^^^^^^^ Object of type `Iterable2` may not be iterable because its `__iter__` attribute (with type `(bound method Iterable2.__iter__() -> Iterator) | None`) may not be callable
 29 |         # TODO: `int` would probably be better here:
 30 |         reveal_type(x)  # revealed: int | Unknown
   |
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_invalid_`next`_method.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_invalid_`next`_method.snap
@@ -51,12 +51,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Iterable1` may not be iterable because its `__iter__` method returns an object of type `Iterator1`, which may have an invalid `__next__` method (expected `def __next__(self): ...`)
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:28:14
   |
 27 |     # error: [not-iterable]
 28 |     for x in Iterable1():
-   |              ^^^^^^^^^^^
+   |              ^^^^^^^^^^^ Object of type `Iterable1` may not be iterable because its `__iter__` method returns an object of type `Iterator1`, which may have an invalid `__next__` method (expected `def __next__(self): ...`)
 29 |         reveal_type(x)  # revealed: int | str
   |

@@ -77,12 +77,12 @@ info: revealed-type: Revealed type
 ```

 ```
-error: lint:not-iterable: Object of type `Iterable2` may not be iterable because its `__iter__` method returns an object of type `Iterator2`, which has a `__next__` attribute that may not be callable
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:32:14
   |
 31 |     # error: [not-iterable]
 32 |     for y in Iterable2():
-   |              ^^^^^^^^^^^
+   |              ^^^^^^^^^^^ Object of type `Iterable2` may not be iterable because its `__iter__` method returns an object of type `Iterator2`, which has a `__next__` attribute that may not be callable
 33 |         # TODO: `int` would probably be better here:
 34 |         reveal_type(y)  # revealed: int | Unknown
   |
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_unbound_`iter`_and_bad_`getitem`_method.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_unbound_`iter`_and_bad_`getitem`_method.snap
@@ -36,12 +36,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Iterable` may not be iterable because it may not have an `__iter__` method and its `__getitem__` method has an incorrect signature for the old-style iteration protocol (expected a signature at least as permissive as `def __getitem__(self, key: int): ...`)
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:18:14
   |
 17 |     # error: [not-iterable]
 18 |     for x in Iterable():
-   |              ^^^^^^^^^^
+   |              ^^^^^^^^^^ Object of type `Iterable` may not be iterable because it may not have an `__iter__` method and its `__getitem__` method has an incorrect signature for the old-style iteration protocol (expected a signature at least as permissive as `def __getitem__(self, key: int): ...`)
 19 |         reveal_type(x)  # revealed: int | bytes
   |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_unbound_`iter`_and_possibly_invalid_`getitem`.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_unbound_`iter`_and_possibly_invalid_`getitem`.snap
@@ -54,12 +54,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Iterable1` may not be iterable because it may not have an `__iter__` method and its `__getitem__` attribute (with type `(bound method Iterable1.__getitem__(item: int) -> str) | None`) may not be callable
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:31:14
   |
 30 |     # error: [not-iterable]
 31 |     for x in Iterable1():
-   |              ^^^^^^^^^^^
+   |              ^^^^^^^^^^^ Object of type `Iterable1` may not be iterable because it may not have an `__iter__` method and its `__getitem__` attribute (with type `(bound method Iterable1.__getitem__(item: int) -> str) | None`) may not be callable
 32 |         # TODO: `bytes | str` might be better
 33 |         reveal_type(x)  # revealed: bytes | str | Unknown
   |
@@ -81,12 +81,12 @@ info: revealed-type: Revealed type
 ```

 ```
-error: lint:not-iterable: Object of type `Iterable2` may not be iterable because it may not have an `__iter__` method and its `__getitem__` method (with type `(bound method Iterable2.__getitem__(item: int) -> str) | (bound method Iterable2.__getitem__(item: str) -> int)`) may have an incorrect signature for the old-style iteration protocol (expected a signature at least as permissive as `def __getitem__(self, key: int): ...`)
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:36:14
   |
 35 |     # error: [not-iterable]
 36 |     for y in Iterable2():
-   |              ^^^^^^^^^^^
+   |              ^^^^^^^^^^^ Object of type `Iterable2` may not be iterable because it may not have an `__iter__` method and its `__getitem__` method (with type `(bound method Iterable2.__getitem__(item: int) -> str) | (bound method Iterable2.__getitem__(item: str) -> int)`) may have an incorrect signature for the old-style iteration protocol (expected a signature at least as permissive as `def __getitem__(self, key: int): ...`)
 37 |         reveal_type(y)  # revealed: bytes | str | int
   |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_unbound_`iter`_and_possibly_unbound_`getitem`.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_unbound_`iter`_and_possibly_unbound_`getitem`.snap
@@ -35,12 +35,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Iterable` may not be iterable because it may not have an `__iter__` method or a `__getitem__` method
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:17:14
   |
 16 |     # error: [not-iterable]
 17 |     for x in Iterable():
-   |              ^^^^^^^^^^
+   |              ^^^^^^^^^^ Object of type `Iterable` may not be iterable because it may not have an `__iter__` method or a `__getitem__` method
 18 |         reveal_type(x)  # revealed: int | bytes
   |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Union_type_as_iterable_where_one_union_element_has_invalid_`iter`_method.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Union_type_as_iterable_where_one_union_element_has_invalid_`iter`_method.snap
@@ -36,13 +36,13 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Test | Test2` may not be iterable because its `__iter__` method returns an object of type `TestIter | int`, which may not have a `__next__` method
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:18:14
   |
 16 |     # TODO: Improve error message to state which union variant isn't iterable (https://github.com/astral-sh/ruff/issues/13989)
 17 |     # error: [not-iterable]
 18 |     for x in Test() if flag else Test2():
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Object of type `Test | Test2` may not be iterable because its `__iter__` method returns an object of type `TestIter | int`, which may not have a `__next__` method
 19 |         reveal_type(x)  # revealed: int
   |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Union_type_as_iterable_where_one_union_element_has_no_`iter`_method.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Union_type_as_iterable_where_one_union_element_has_no_`iter`_method.snap
@@ -31,13 +31,13 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Test | Literal[42]` may not be iterable because it may not have an `__iter__` method and it doesn't have a `__getitem__` method
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:13:14
   |
 11 | def _(flag: bool):
 12 |     # error: [not-iterable]
 13 |     for x in Test() if flag else 42:
-   |              ^^^^^^^^^^^^^^^^^^^^^^
+   |              ^^^^^^^^^^^^^^^^^^^^^^ Object of type `Test | Literal[42]` may not be iterable because it may not have an `__iter__` method and it doesn't have a `__getitem__` method
 14 |         reveal_type(x)  # revealed: int
   |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_With_non-callable_iterator.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_With_non-callable_iterator.snap
@@ -33,25 +33,25 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `NotIterable` is not iterable because its `__iter__` attribute has type `int | None`, which is not callable
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:11:14
   |
 10 |     # error: [not-iterable]
 11 |     for x in NotIterable():
-   |              ^^^^^^^^^^^^^
+   |              ^^^^^^^^^^^^^ Object of type `NotIterable` is not iterable because its `__iter__` attribute has type `int | None`, which is not callable
 12 |         pass
   |

 ```

 ```
-warning: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+warning: lint:possibly-unresolved-reference
  --> /src/mdtest_snippet.py:16:17
   |
 14 |     # revealed: Unknown
 15 |     # error: [possibly-unresolved-reference]
 16 |     reveal_type(x)
-   |                 ^
+   |                 ^ Name `x` used when possibly not defined
   |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_`iter`_does_not_return_an_iterator.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_`iter`_does_not_return_an_iterator.snap
@@ -26,12 +26,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Bad` is not iterable because its `__iter__` method returns an object of type `int`, which has no `__next__` method
+error: lint:not-iterable
 --> /src/mdtest_snippet.py:8:10
  |
 7 | # error: [not-iterable]
 8 | for x in Bad():
-  |          ^^^^^
+  |          ^^^^^ Object of type `Bad` is not iterable because its `__iter__` method returns an object of type `int`, which has no `__next__` method
 9 |     reveal_type(x)  # revealed: Unknown
  |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_`iter`_method_with_a_bad_signature.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_`iter`_method_with_a_bad_signature.snap
@@ -30,12 +30,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Iterable` is not iterable because its `__iter__` method has an invalid signature (expected `def __iter__(self): ...`)
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:12:10
   |
 11 | # error: [not-iterable]
 12 | for x in Iterable():
-   |          ^^^^^^^^^^
+   |          ^^^^^^^^^^ Object of type `Iterable` is not iterable because its `__iter__` method has an invalid signature (expected `def __iter__(self): ...`)
 13 |     reveal_type(x)  # revealed: int
   |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_`iter`_returns_an_iterator_with_an_invalid_`next`_method.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_`iter`_returns_an_iterator_with_an_invalid_`next`_method.snap
@@ -41,12 +41,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/loops/for.md
 # Diagnostics

 ```
-error: lint:not-iterable: Object of type `Iterable1` is not iterable because its `__iter__` method returns an object of type `Iterator1`, which has an invalid `__next__` method (expected `def __next__(self): ...`)
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:19:10
   |
 18 | # error: [not-iterable]
 19 | for x in Iterable1():
-   |          ^^^^^^^^^^^
+   |          ^^^^^^^^^^^ Object of type `Iterable1` is not iterable because its `__iter__` method returns an object of type `Iterator1`, which has an invalid `__next__` method (expected `def __next__(self): ...`)
 20 |     reveal_type(x)  # revealed: int
   |

@@ -67,12 +67,12 @@ info: revealed-type: Revealed type
 ```

 ```
-error: lint:not-iterable: Object of type `Iterable2` is not iterable because its `__iter__` method returns an object of type `Iterator2`, which has a `__next__` attribute that is not callable
+error: lint:not-iterable
  --> /src/mdtest_snippet.py:23:10
   |
 22 | # error: [not-iterable]
 23 | for y in Iterable2():
-   |          ^^^^^^^^^^^
+   |          ^^^^^^^^^^^ Object of type `Iterable2` is not iterable because its `__iter__` method returns an object of type `Iterator2`, which has a `__next__` attribute that is not callable
 24 |     reveal_type(y)  # revealed: Unknown
   |

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/instances.md_-_Binary_operations_on_instances_-_Operations_involving_types_with_invalid_`bool`_methods.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/instances.md_-_Binary_operations_on_instances_-_Operations_involving_types_with_invalid_`bool`_methods.snap
@@ -24,13 +24,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/binary/instances.m
 # Diagnostics

 ```
-error: lint:unsupported-bool-conversion: Boolean conversion is unsupported for type `NotBoolable`
+error: lint:unsupported-bool-conversion
 --> /src/mdtest_snippet.py:7:8
  |
 6 | # error: [unsupported-bool-conversion]
 7 | 10 and a and True
-  |        ^
+  |        ^ Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable
  |
-info: `__bool__` on `NotBoolable` must be callable

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/membership_test.md_-_Comparison___Membership_Test_-_Return_type_that_doesn't_implement_`bool`_correctly.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/membership_test.md_-_Comparison___Membership_Test_-_Return_type_that_doesn't_implement_`bool`_correctly.snap
@@ -28,28 +28,26 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/comparison/instanc
 # Diagnostics

 ```
-error: lint:unsupported-bool-conversion: Boolean conversion is unsupported for type `NotBoolable`
+error: lint:unsupported-bool-conversion
  --> /src/mdtest_snippet.py:9:1
   |
 8 | # error: [unsupported-bool-conversion]
 9 | 10 in WithContains()
-   | ^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^ Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable
 10 | # error: [unsupported-bool-conversion]
 11 | 10 not in WithContains()
   |
-info: `__bool__` on `NotBoolable` must be callable

 ```

 ```
-error: lint:unsupported-bool-conversion: Boolean conversion is unsupported for type `NotBoolable`
+error: lint:unsupported-bool-conversion
  --> /src/mdtest_snippet.py:11:1
   |
 9 | 10 in WithContains()
 10 | # error: [unsupported-bool-conversion]
 11 | 10 not in WithContains()
-   | ^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^ Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable
   |
-info: `__bool__` on `NotBoolable` must be callable

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/no_matching_overload.md_-_No_matching_overload_diagnostics_-_Calls_to_overloaded_functions.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/no_matching_overload.md_-_No_matching_overload_diagnostics_-_Calls_to_overloaded_functions.snap
@@ -18,11 +18,11 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/no_mat
 # Diagnostics

 ```
-error: lint:no-matching-overload: No overload of class `type` matches arguments
+error: lint:no-matching-overload
 --> /src/mdtest_snippet.py:1:1
  |
 1 | type("Foo", ())  # error: [no-matching-overload]
-  | ^^^^^^^^^^^^^^^
+  | ^^^^^^^^^^^^^^^ No overload of class `type` matches arguments
  |

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/not.md_-_Unary_not_-_Object_that_implements_`bool`_incorrectly.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/not.md_-_Unary_not_-_Object_that_implements_`bool`_incorrectly.snap
@@ -22,13 +22,12 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/unary/not.md
 # Diagnostics

 ```
-error: lint:unsupported-bool-conversion: Boolean conversion is unsupported for type `NotBoolable`
+error: lint:unsupported-bool-conversion
 --> /src/mdtest_snippet.py:5:1
  |
 4 | # error: [unsupported-bool-conversion]
 5 | not NotBoolable()
-  | ^^^^^^^^^^^^^^^^^
+  | ^^^^^^^^^^^^^^^^^ Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable
  |
-info: `__bool__` on `NotBoolable` must be callable

 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/protocols.md_-_Protocols_-_Calls_to_protocol_classes.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/protocols.md_-_Protocols_-_Calls_to_protocol_classes.snap
@@ -1,117 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: protocols.md - Protocols - Calls to protocol classes
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/protocols.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
- 1 | from typing_extensions import Protocol, reveal_type
- 2 | 
- 3 | # error: [call-non-callable]
- 4 | reveal_type(Protocol())  # revealed: Unknown
- 5 | 
- 6 | class MyProtocol(Protocol):
- 7 |     x: int
- 8 | 
- 9 | # error: [call-non-callable] "Cannot instantiate class `MyProtocol`"
-10 | reveal_type(MyProtocol())  # revealed: MyProtocol
-11 | class SubclassOfMyProtocol(MyProtocol): ...
-12 | 
-13 | reveal_type(SubclassOfMyProtocol())  # revealed: SubclassOfMyProtocol
-14 | def f(x: type[MyProtocol]):
-15 |     reveal_type(x())  # revealed: MyProtocol
-```
-
-# Diagnostics
-
-```
-error: lint:call-non-callable: Object of type `typing.Protocol` is not callable
- --> /src/mdtest_snippet.py:4:13
-  |
-3 | # error: [call-non-callable]
-4 | reveal_type(Protocol())  # revealed: Unknown
-  |             ^^^^^^^^^^
-5 |
-6 | class MyProtocol(Protocol):
-  |
-
-```
-
-```
-info: revealed-type: Revealed type
- --> /src/mdtest_snippet.py:4:1
-  |
-3 | # error: [call-non-callable]
-4 | reveal_type(Protocol())  # revealed: Unknown
-  | ^^^^^^^^^^^^^^^^^^^^^^^ `Unknown`
-5 |
-6 | class MyProtocol(Protocol):
-  |
-
-```
-
-```
-error: lint:call-non-callable: Cannot instantiate class `MyProtocol`
-  --> /src/mdtest_snippet.py:10:13
-   |
- 9 | # error: [call-non-callable] "Cannot instantiate class `MyProtocol`"
-10 | reveal_type(MyProtocol())  # revealed: MyProtocol
-   |             ^^^^^^^^^^^^ This call will raise `TypeError` at runtime
-11 | class SubclassOfMyProtocol(MyProtocol): ...
-   |
-info: Protocol classes cannot be instantiated
- --> /src/mdtest_snippet.py:6:7
-  |
-4 | reveal_type(Protocol())  # revealed: Unknown
-5 |
-6 | class MyProtocol(Protocol):
-  |       ^^^^^^^^^^^^^^^^^^^^ `MyProtocol` declared as a protocol here
-7 |     x: int
-  |
-
-```
-
-```
-info: revealed-type: Revealed type
-  --> /src/mdtest_snippet.py:10:1
-   |
- 9 | # error: [call-non-callable] "Cannot instantiate class `MyProtocol`"
-10 | reveal_type(MyProtocol())  # revealed: MyProtocol
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^ `MyProtocol`
-11 | class SubclassOfMyProtocol(MyProtocol): ...
-   |
-
-```
-
-```
-info: revealed-type: Revealed type
-  --> /src/mdtest_snippet.py:13:1
-   |
-11 | class SubclassOfMyProtocol(MyProtocol): ...
-12 |
-13 | reveal_type(SubclassOfMyProtocol())  # revealed: SubclassOfMyProtocol
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `SubclassOfMyProtocol`
-14 | def f(x: type[MyProtocol]):
-15 |     reveal_type(x())  # revealed: MyProtocol
-   |
-
-```
-
-```
-info: revealed-type: Revealed type
-  --> /src/mdtest_snippet.py:15:5
-   |
-13 | reveal_type(SubclassOfMyProtocol())  # revealed: SubclassOfMyProtocol
-14 | def f(x: type[MyProtocol]):
-15 |     reveal_type(x())  # revealed: MyProtocol
-   |     ^^^^^^^^^^^^^^^^ `MyProtocol`
-   |
-
-```
--- a/Show More
+++ b/Show More