[Adityakk9031]

Skip POSIX-only supervisor and task runner tests on Windows using pytestmark rather than stubbing out POSIX syscalls. CI on Linux runs all tests as normal.

Per maintainer request (@potiuk), the Windows compatibility changes have been split into separate, focused PRs:

• Prek explicit UTF-8 encoding in common_prek_utils.py: Ensure explicit UTF-8 encoding in prek scripts for Windows compatibility #73679
• Shared stats register_at_fork guard: Observability: Guard register_at_fork in shared stats for Windows compatibility #73680
• Task SDK POSIX test skips (this PR)

Related to #69464 (not closing it).

[Adityakk9031]

@potiuk have a look

[potiuk]

Please split those even further - each for different area. Some of them some prek, some tests, some production.

[uros-b]

@Adityakk9031 Please fix the PR title, otherwise code changes look good!

[github-actions]

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[Adityakk9031]

@uros-b changed please merge it

[uros-b]

Thank you @Adityakk9031, please ping @potiuk here for further review

[Adityakk9031]

@potiuk @uros-b Per feedback, I have split the changes into focused micro-PRs by area:

• Prek / Dev tools: Ensure explicit UTF-8 encoding in prek scripts for Windows compatibility #73679
• Observability / Shared: Observability: Guard register_at_fork in shared stats for Windows compatibility #73680
• Task SDK Tests (This PR): Scoped strictly to skipping POSIX-only supervisor and task runner tests on Windows.

[potiuk]

Thanks for splitting this up. The scope is right now: only the test skips, with the prek and shared/stats parts in their own PRs. The skips themselves need to be narrower:

1. test_task_runner.py: the module-wide skip hides about 187 tests, but task_runner.py uses no POSIX-only process primitives that I can find. It only installs a SIGTERM handler, which exists on Windows, and timeout.py already falls back when SIGALRM is missing. Could you share which tests actually fail on Windows (a pytest summary with the errors), and mark only those, with a reason that names the API involved?
2. test_supervisor.py already uses precise per-test markers (around lines 5145–5246, and the win32 skip at 5412). Please follow that pattern: mark the classes or tests that spawn processes (os.fork / posix_spawn / setpgid / killpg) rather than the whole module, so tests that don't need POSIX keep running.
3. The description says "Close: #69464", but that issue is the Sentry before_send bug and unrelated to this change. Please remove or fix the reference so merging doesn't close it.

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Drafted-by: Claude Code (Opus 5); reviewed by @potiuk before posting

[kaxil]

@Adityakk9031 I don't think we say anywhere that Airflow support Windows!

If your goal is to ensure it runs with Windows, please upload a demo window or screenshot of it working end to end