Bug report

Bug description:

This should always print True, that is an attribute accessed from a class should match the value that's in the type's mappingproxy:

classX:def__del__(inner_self):v=C.aprint(v==C.__dict__['a'])classC:a=X()# prime the cacheC.aC.a# destructor shouldn't be able to see inconsisent stateC.a=X()C.a=X()

But this prints False because the destructor can be run when the assignment into the type dict occurs, but before the type version is invalidated.

CPython versions tested on:

3.8, CPython main branch

Operating systems tested on:

Linux