TypeAliasType.__type_params__ can return forms from typing_extensions #13663

	name: Stdlib stubtest

	on:
	workflow_dispatch:
	push:
	branches:
	- main
	pull_request:
	paths:
	- "stdlib/**"
	- ".github/workflows/stubtest_stdlib.yml"
	- "tests/**"
	# When requirements.txt changes, we run `daily.yml`, which includes stdlib stubtest

	permissions:
	contents: read

	env:
	PIP_DISABLE_PIP_VERSION_CHECK: 1
	FORCE_COLOR: 1
	TERM: xterm-256color # needed for FORCE_COLOR to work on mypy on Ubuntu, see https://github.com/python/mypy/issues/13817

	concurrency:
	group: ${{ github.workflow }}-${{ github.head_ref \|\| github.run_id }}
	cancel-in-progress: true

	jobs:
	stubtest-stdlib:
	name: "stubtest: stdlib"
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	os: ["ubuntu-latest", "windows-latest", "macos-latest"]
	python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
	fail-fast: false

	steps:
	- uses: actions/checkout@v5
	- name: Set up Python ${{ matrix.python-version }} on ${{ matrix.os }}
	uses: actions/setup-python@v6
	with:
	python-version: ${{ matrix.python-version }}
	cache: pip
	cache-dependency-path: requirements-tests.txt
	allow-prereleases: true
	check-latest: true
	- name: Install dependencies
	run: pip install -r requirements-tests.txt
	# Temporary to get @disjoint_base support; can remove once mypy 1.18 is released
	- name: Install mypy from git
	run: pip install git+https://github.com/python/mypy.git@116b92bae7b5dbf5e6bd36fd9b0c6804973e5554
	- name: Run stubtest
	run: python tests/stubtest_stdlib.py

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