Generic Type[T] function argument rejected as base class

Bug Report

Since https://github.com/python/mypy/issues/5865 was fixed, the following code now type checks:

from typing import Any, Type


def f(typ: Type[Any]) -> Type[Any]:
    class C(typ):
        pass

    return C

However if we make the superclass generic, it doesn't type check anymore which I would expect it to do.

To Reproduce

from typing import Type, TypeVar

T = TypeVar("T")


def f(typ: Type[T]) -> Type[T]:
    class C(typ):
        pass

    return C

Actual Behavior

mypy_return_type.py:7: error: Variable "typ" is not valid as a type  [valid-type]
mypy_return_type.py:7: note: See https://mypy.readthedocs.io/en/stable/common_issues.html#variables-vs-type-aliases
mypy_return_type.py:7: error: Invalid base class "typ"  [misc]
Found 2 errors in 1 file (checked 1 source file)

Your Environment

• Mypy version used: 1.0.0+dev.e9f5858c44b61c2d02819940debe3c31d099f9d5
• Mypy command-line flags: mypy mypy_return_type.py
• Mypy configuration options from mypy.ini (and other config files): None
• Python version used: 3.10.9

提供された汎用の Type[T] の例を mypy mypy_return_type.py で再現し、その後、基底クラスとして使用される変数式の型チェックの経路を追跡して、非汎用の Type[Any] のケースと比較します。完了条件は、汎用の例が valid-type と Invalid base class のエラーなしに型チェックを通過し、Type[T] の戻り値型を維持することです。