Module Aliases for PEP 561 not working

[alanhdu]

Using the mypy's master branch (219fbf8) and pip installing https://github.com/numpy/numpy-stubs (a PEP 561 package), running mypy on the following code:

import numpy as np

def f(x: np.ndarray):
    reveal_type(x)

outputs:

test.py:4: error: Revealed type is 'Any'

But if I do:

from numpy import ndarray

def f(x: ndarray):
    reveal_type(x)

then I get the expected

test.py:4: error: Revealed type is 'numpy.ndarray'

[alanhdu]

Note that this example works perfectly fine with mypy 0.610. I ran a git bisect and believe that d91efd4 introduced the current behavior.

[emmatyping]

Confirmed the bisect, and it is happening on master.

The issue is this part here: https://github.com/python/mypy/blob/master/mypy/semanal.py#L3081. It appears that adding the __getattr__ check is too earnest, it does not allow for re-binding that occurs on line 3098.