When I say extremely slow I really mean it. It takes about half a minute for it the print the error in the following very simple code:
def aaa(a: int, b: int, c: int) -> int:
return 1
print(aaa(1, 2, 3, 4, 5))
For real code it takes forever, after several minutes waiting I gave up on waiting for it to end. I tried doing a pip install --upgrade --force-reinstall mypy but that didn't change anything.