mypy Cannot find implementation or library stub for module

I have:

foo/├── __init__.py├── bar.py└── baz├── __init__.py└── alice.py

In bar.py, I import Alice, which is an empty class with nothing in it but the name attribute set to "Alice".

from baz.alice import Alicea = Alice()print(a.name)

This runs properly:

$ python foo/bar.pyAlice

But mypy complains:

$ mypy --versionmypy 0.910$ mypy --strict .foo/bar.py:1: error: Cannot find implementation or library stub for module named "baz.alice"foo/bar.py:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-importsFound 1 error in 1 file (checked 6 source files)

Why is mypy complaining?