Argument 1 to "join" of "str" has incompatible type "Callable[[], List[str]]"; expected "Iterable[str]"

[willigott]

Bug Report

I receive an unexpected error when running mypy related to a @classmethod exposed as @property of a class that inherits from Enum.

To Reproduce

from enum import Enum
from typing import List


class Stuff(Enum):
    A = 'something'
    B = 'something_else'
    C = 'even_more'
    
    @classmethod
    @property
    def important_stuff(cls) -> List[str]:
        return [cls.A.value, cls.C.value]


print(f'{", ".join(Stuff.important_stuff)}')

Expected Behavior

As important_stuff always returns a list of strings, I would not expect any error to occur.

Actual Behavior
I receive an error

error: Argument 1 to "join" of "str" has incompatible type "Callable[[], List[str]]"; expected "Iterable[str]"

Your Environment

• Mypy version used: 0.910
• Mypy command-line flags: none
• Mypy configuration options from mypy.ini (and other config files): none
• Python version used: 3.9.5
• Operating system and version: Ubuntu 20.04

The question was also asked on stackoverflow which also includes a workaround: click.

[soma2000-lang]

@jonshea I am workingon this

[hauntsaninja]

Duplicate of #11619 , note that CPython might remove support for this