Internal Error with recursive TypeAlias + TypeVar when in function scope

[ShadowLNC]

Crash Report

I declared a recursive TypeAlias inside a function, and bound a TypeVar to that TypeAlias. Using the TypeVar seems to cause the crash (if I don't reference the TypeVar then mypy points out "Recursive types are not allowed at function scope").

After looking into this, I am now aware that what I was trying to do is explicitly forbidden by PEP-613 😅

(If I explicitly set the type to TypeAlias in the function (i.e. I specify foo: TypeAlias in my example), then Pylance/VSCode shows the error "A TypeAlias can be defined only within a module or class scope", but mypy still crashes.)

When I move the TypeAlias declaration outside of the function, in compliance with PEP-613, everything works again. (I can leave the TypeVar inside and it's fine.)

Traceback

$ mypy repro.py --show-traceback
repro.py:8: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 1.2.0
Traceback (most recent call last):
  File "mypy/semanal.py", line 6272, in accept
  File "mypy/nodes.py", line 774, in accept
  File "mypy/semanal.py", line 831, in visit_func_def
  File "mypy/semanal.py", line 863, in analyze_func_def
  File "mypy/typeanal.py", line 944, in visit_callable_type
  File "mypy/typeanal.py", line 1549, in anal_var_defs
  File "mypy/typeanal.py", line 1541, in anal_var_def
  File "mypy/types.py", line 2847, in accept
  File "mypy/typeanal.py", line 1112, in visit_placeholder_type
  File "mypy/semanal.py", line 5586, in lookup_fully_qualified
  File "mypy/semanal.py", line 5602, in lookup_fully_qualified_or_none
AssertionError: 
repro.py:8: : note: use --pdb to drop into pdb

To Reproduce

from typing import TypeVar


def dummy() -> None:
    foo = int | str | dict[str, "foo"]
    T = TypeVar("T", bound=foo)

    def bar(x: T) -> T:
        pass

Your Environment

• Mypy version used: 1.2.0 (also seen with 0.991)
• Mypy command-line flags: None
• Mypy configuration options from mypy.ini (and other config files): None (removed them to reproduce the issue)
• Python version used: 3.11
• Operating system and version: MacOS 13.2.1 Ventura