`--ignoreexternal --verifytypes` false positive with manual `TypeAliasType`

[jorenham]

Consider the following valid project with a py.typed and an __init__.py like:

from decimal import Decimal
from fractions import Fraction
from typing_extensions import TypeAliasType

Real = TypeAliasType("Real", float | Decimal | Fraction)

__all__ = ("Real",)

Because of typeshed issues, we need to run --verifytypes in combination with --ignoreexternal. But even though this should be valid, an error is reported:

$ uv run pyright --ignoreexternal --verifytypes demo
Module name: "demo"
Package directory: "~/Workspace/pyright-verifytypes-typealiastype/demo"
Module directory: "~/Workspace/pyright-verifytypes-typealiastype/demo"
Path of py.typed file: "~/Workspace/pyright-verifytypes-typealiastype/demo/py.typed"

Public modules: 1
   demo

Symbols used in public interface:
demo.Real
  ~/Workspace/pyright-verifytypes-typealiastype/demo/__init__.py:20:1 - error: Type is missing type annotation and could be inferred differently by type checkers
    Inferred type is "Real"

Symbols exported by "demo": 2
  With known type: 1
  With ambiguous type: 1
  With unknown type: 0
    (Ignoring unknown types imported from other packages)

Other symbols referenced but not exported by "demo": 0
  With known type: 0
  With ambiguous type: 0
  With unknown type: 0

Symbols without documentation:
  Functions without docstring: 0
  Functions without default param: 0
  Classes without docstring: 0

Type completeness score: 50%

This error disappears if we replace the alias with a Real: TypeAlias = ... or type Real = ... on Python 3.12+.

See https://github.com/jorenham/pyright-verifytypes-typealiastype for a repoduction of this issue.

[erictraut]

Thanks for the bug report. This will be addressed in the next release.

[erictraut]

This is addressed in pyright 1.1.389