TypeAliasType doesn't have __qualname__

[Kludex]

Hi there 👋

I'm not sure where to post this, so I'm posting here, hoping for instructions.

The following code doesn't work on Python 3.12, but works on previous versions:

from typing_extensions import TypeAliasType, TypeVar

# type A[T] = set[T] | list[T]

T = TypeVar("T")
A = TypeAliasType("A", set[T] | list[T], type_params=(T,))
print(A[int].__qualname__)

On 3.12, I don't have __qualname__ on TypeAliasType. The error I have is:

❯ python ../main.py          
Traceback (most recent call last):
  File "/Users/marcelotryle/dev/pydantic/pydantic/../main.py", line 7, in <module>
    print(A[int].__qualname__)
          ^^^^^^^^^^^^^^^^^^^
AttributeError: 'typing.TypeAliasType' object has no attribute '__qualname__'

It also fails if you use the 3.12 syntax.

Is this a bug?

[sobolevn]

CC @JelleZijlstra