Missing argument to Callable crashes mypy

[spkersten]

This code (missing return type in Callable) crashes mypy with an uncaught IndexError:

from typing import Callable

def g(f: Callable[[int]]) -> None:
    pass

It should just report an error.

[JukkaL]

Yes, it definitely should not crash. Thanks for the bug report!

[gvanrossum]

FWIW bare Callable it should probably be equivalent to Callable[..., Any]. See python/typing#133

[JukkaL]

This no longer crashes.