Bug report

Bug description:

Consider this package:

$ ls recmod/__main__.pya.pyb.py$ cat recmod/__main__.py from . import aprint(a.__annotations__)$ cat recmod/a.py v1: intfrom . import bv2: int$ cat recmod/b.py from . import aprint(a.__annotations__)

On 3.13, this produces:

$ python3.13 -m recmod{'v1': <class 'int'>}{'v1': <class 'int'>, 'v2': <class 'int'>}

But on main, we get this:

$ ~/py/cpython/python.exe -m recmod{}{}

This is because we only set the__annotate__ function at the end of the module execution, so when we access annotations on the partially executed module a (inb.py), there aren't any yet. But this also populates the__annotations__ cache, so even accesses to__annotations__ after a has been fully executed still return an empty dictionary.

Should we fix this and how? I don't care much what happens if you access__annotations__ while the module is partially evaluated. However, it seems bad that such access poisons the cache forever. To fix that, we should makeModuleType.__annotations__ not cache its return value if the module is not yet fully evaluated.

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS

Linked PRs

• gh-130907: Treat all module-level annotations as conditional #131550