False positive on mutual recursion involving a type alias

[JelleZijlstra]

This produces an error but (I think) shouldn't:

from typing import List

class A(object):
    b: 'B'  # E: Invalid type "recurse.B"

B = List[A]

It works fine if I make B a class, even a class inheriting from A. I encountered this in https://github.com/JelleZijlstra/typeshed_client/blob/master/typeshed_client/parser.py#L30 (A is NameInfo and B is NameDict).

[ilevkivskyi]

I think this is essentially a duplicate of #2241. It is actually more difficult than it may look. It is "entangled" with several other issues with forward references and might need another pass in semanal.py (I am going to work on this after the protocol PR is merged).

I propose to close this issue and track this in #2241 (after copying this example there). Do you agree?

[JelleZijlstra]

Thanks, you're right. Sorry for missing the duplicate.