Have you tried if the fix at issue7105 solves the problem? I don't see the patch there introduce a `clear` method override for WeakValueDictionary or WeakKeyDictionary. The one for WeakSet still calls self.data.clear(), which for dictionaries would still result in the problem in this ticket (but not for WeakSet, because clearing a WeakSet shouldn't decref anything other than the weak references stored in the underlying set).