diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py index f35f864dce21e86..b0d468b34092b25 100644 --- a/Lib/test/test_typing.py +++ b/Lib/test/test_typing.py @@ -10299,6 +10299,17 @@ def test_args_kwargs(self): self.assertEqual(repr(P.args), "P.args") self.assertEqual(repr(P.kwargs), "P.kwargs") + def test_args_kwargs_weakrefs(self): + P = ParamSpec('P') + for attr_name in ('args', 'kwargs'): + with self.subTest(attr_name=attr_name): + callback_fired = [] + attr = getattr(P, attr_name) + ref = weakref.ref(attr, lambda _: callback_fired.append(True)) + del attr + self.assertEqual(callback_fired, [True]) + self.assertIsNone(ref()) + def test_stringized(self): P = ParamSpec('P') class C(Generic[P]): diff --git a/Misc/NEWS.d/next/Library/2026-09-16-14-04-38.gh-issue-157621.R6v2S8.rst b/Misc/NEWS.d/next/Library/2026-09-16-14-04-38.gh-issue-157621.R6v2S8.rst new file mode 100644 index 000000000000000..b8342da0faebb91 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-09-16-14-04-38.gh-issue-157621.R6v2S8.rst @@ -0,0 +1,2 @@ +Fix a crash when a weak-reference callback is attached to a +:class:`typing.ParamSpecArgs` or :class:`typing.ParamSpecKwargs` instance. diff --git a/Objects/typevarobject.c b/Objects/typevarobject.c index 53c350838969616..eed1457cbb426d9 100644 --- a/Objects/typevarobject.c +++ b/Objects/typevarobject.c @@ -958,6 +958,7 @@ paramspecattr_dealloc(PyObject *self) _PyObject_GC_UNTRACK(self); Py_XDECREF(psa->__origin__); + PyObject_ClearWeakRefs(self); Py_TYPE(self)->tp_free(self); Py_DECREF(tp);