isinstance(value, Callable) is flagged as an error

[mthuurne]

Bug Report

When using isinstance(value, Callable), mypy flags it as an error, claiming that Callable is a typing special form. While it is an error to use a specialized form of Callable such as Callable[[int], str], the generic class is valid for isinstance checks.

To Reproduce

Run mypy on the following code: (playground)

from collections.abc import Callable

def check(factory: Callable) -> None:
    if not isinstance(factory, Callable):
        raise TypeError("'factory' is not callable")

I also tried importing Callable from typing instead of collections.abc, but that doesn't make a difference.

Expected Behavior

No error is reported, as this construct executes fine and does what is expected: checking whether the object is callable.

Actual Behavior

testcase.py:4: error: Argument 2 to "isinstance" has incompatible type "<typing special form>"; expected "_ClassInfo"  [arg-type]
        if not isinstance(factory, Callable):
                                   ^~~~~~~~

Your Environment

• Mypy version used: 1.1.1
• Python version used: 3.10.6

[AlexWaygood]

Duplicate of #3060

[AlexWaygood]

Duplicate of #3060

(#3060 concerns typing.Type rather than Callable, but it's the same error message on mypy 1.1.1, and it's caused by the same underlying bug)