In the following layout:
[mypy]
disallow_untyped_defs = True
[mypy-a.b.*]
disallow_untyped_defs = False
a contains __init__.py and a directory a/b
a/b contains c.py with an untyped def
Mypy will complain about missing type annotations in a.b.c. If I create a/b/__init__.py, the errors go away. This is a regression in v0.800.