remove continue-on-error from free-threaded CI job (#4546)

* remove continue-on-error from free-threaded CI job

* fix diagnostic message `cfg_attrs`

* disable assert that may not be true on free-threaded build

* Update ci.yml

Co-authored-by: David Hewitt <mail@davidhewitt.dev>

---------

Co-authored-by: David Hewitt <mail@davidhewitt.dev>

.github/workflows/ci.yml

@@ -520,12 +520,7 @@ jobs:
       - run: python3 -m sysconfig
       - run: python3 -m pip install --upgrade pip && pip install nox
       - run: nox -s ffi-check
-      - name: Run default nox sessions that should pass
-        run: nox -s clippy docs rustfmt ruff
-      - name: Run PyO3 tests with free-threaded Python (can fail)
-        # TODO fix the test crashes so we can unset this
-        continue-on-error: true
-        run: nox -s test
+      - run: nox
 
   test-version-limits:
     needs: [fmt]

src/impl_/pyclass.rs

@@ -1115,7 +1115,7 @@ impl<T> PyClassThreadChecker<T> for ThreadCheckerImpl {
 /// Trait denoting that this class is suitable to be used as a base type for PyClass.
 
 #[cfg_attr(
-    all(diagnostic_namespace, feature = "abi3"),
+    all(diagnostic_namespace, Py_LIMITED_API),
     diagnostic::on_unimplemented(
         message = "pyclass `{Self}` cannot be subclassed",
         label = "required for `#[pyclass(extends={Self})]`",
@@ -1124,7 +1124,7 @@ impl<T> PyClassThreadChecker<T> for ThreadCheckerImpl {
     )
 )]
 #[cfg_attr(
-    all(diagnostic_namespace, not(feature = "abi3")),
+    all(diagnostic_namespace, not(Py_LIMITED_API)),
     diagnostic::on_unimplemented(
         message = "pyclass `{Self}` cannot be subclassed",
         label = "required for `#[pyclass(extends={Self})]`",

tests/test_gc.rs

@@ -120,6 +120,10 @@ fn gc_integration() {
     Python::with_gil(|py| {
         py.run(ffi::c_str!("import gc; gc.collect()"), None, None)
             .unwrap();
+        // threads are resumed before tp_clear() calls finish, so drop might not
+        // necessarily be called when we get here see
+        // https://peps.python.org/pep-0703/#stop-the-world
+        #[cfg(not(Py_GIL_DISABLED))]
         assert!(drop_called.load(Ordering::Relaxed));
     });
 }