[red-knot] Add test case for read on tracked struct being initialized

Cargo.lock

@@ -490,20 +490,6 @@ 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"
@@ -2572,7 +2558,7 @@ dependencies = [
  "anyhow",
  "bitflags 2.9.0",
  "camino",
- "compact_str 0.9.0",
+ "compact_str",
  "countme",
  "dir-test",
  "drop_bomb",
@@ -2661,6 +2647,7 @@ dependencies = [
  "tempfile",
  "thiserror 2.0.12",
  "toml",
+ "tracing",
 ]
 
 [[package]]
@@ -3101,7 +3088,7 @@ version = "0.0.0"
 dependencies = [
  "aho-corasick",
  "bitflags 2.9.0",
- "compact_str 0.9.0",
+ "compact_str",
  "is-macro",
  "itertools 0.14.0",
  "memchr",
@@ -3199,7 +3186,7 @@ dependencies = [
  "anyhow",
  "bitflags 2.9.0",
  "bstr",
- "compact_str 0.9.0",
+ "compact_str",
  "insta",
  "memchr",
  "ruff_annotate_snippets",
@@ -3457,11 +3444,10 @@ checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 
 [[package]]
 name = "salsa"
-version = "0.19.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=87bf6b6c2d5f6479741271da73bd9d30c2580c26#87bf6b6c2d5f6479741271da73bd9d30c2580c26"
+version = "0.20.0"
 dependencies = [
  "boxcar",
- "compact_str 0.8.1",
+ "compact_str",
  "crossbeam-queue",
  "dashmap 6.1.0",
  "hashbrown 0.15.2",
@@ -3480,13 +3466,11 @@ dependencies = [
 
 [[package]]
 name = "salsa-macro-rules"
-version = "0.19.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=87bf6b6c2d5f6479741271da73bd9d30c2580c26#87bf6b6c2d5f6479741271da73bd9d30c2580c26"
+version = "0.20.0"
 
 [[package]]
 name = "salsa-macros"
-version = "0.19.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=87bf6b6c2d5f6479741271da73bd9d30c2580c26#87bf6b6c2d5f6479741271da73bd9d30c2580c26"
+version = "0.20.0"
 dependencies = [
  "heck",
  "proc-macro2",

Cargo.toml

@@ -124,7 +124,8 @@ 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 = "87bf6b6c2d5f6479741271da73bd9d30c2580c26" }
+#salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "87bf6b6c2d5f6479741271da73bd9d30c2580c26" }
+salsa = { path = "../salsa" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }

crates/red_knot_python_semantic/resources/mdtest/cycle_panic.md

@@ -0,0 +1,12 @@
+# Cycle panic in tracked struct
+
+```toml
+log=true
+```
+
+## Case
+
+```py
+class Foo[T: Foo, U: (Foo, Foo)]:
+    pass
+```

crates/red_knot_test/Cargo.toml

@@ -34,6 +34,7 @@ serde = { workspace = true }
 tempfile = { workspace = true }
 toml = { workspace = true }
 thiserror = { workspace = true }
+tracing = { workspace = true }
 
 [lints]
 workspace = true

crates/red_knot_test/src/db.rs

@@ -96,7 +96,18 @@ impl SemanticDb for Db {
 
 #[salsa::db]
 impl salsa::Database for Db {
-    fn salsa_event(&self, _event: &dyn Fn() -> salsa::Event) {}
+    fn salsa_event(&self, event: &dyn Fn() -> salsa::Event) {
+        if !tracing::enabled!(tracing::Level::TRACE) {
+            return;
+        }
+
+        let event = event();
+        if matches!(event.kind, salsa::EventKind::WillCheckCancellation) {
+            return;
+        }
+
+        tracing::trace!("Salsa event: {event:?}");
+    }
 }
 
 impl DbWithWritableSystem for Db {