TypeAliasType is the type of what you get when you use the type keyword, eg:

type Point = tuple[float, float]

It is valid (or at least mypy and pyright allow you to) to pass the resultant type alias (Point in the example above) to functions, in which case it is supposed to have a type of TypeAliasType, However, annotating a function argument as TypeAliasType produces an error in PyType:

from typing import TypeAliasType

def f (t: TypeAliasType) -> None:
  pass

here is the error:

tat.py:3:1: error: in <module>: Invalid type annotation '<instance of Callable>'  [invalid-annotation]
  Not a type

def f (t: TypeAliasType) -> None:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  pass
~~~~~~

Pyright and mypy don't error on this code, as I've implied.

Possibly related issues:

#1475 (I guess Python 3.12 support is not truly complete until you can do this?)

#1295 (possibly similar decay-to-callable issue?)