[bug] Windows build fails with MSVC 14.51 — permission_handler_windows uses deprecated <experimental/coroutine>

[ashifali3147]

Summary

The "Build for Flutter Windows" CI job is failing on all PRs since the windows-latest runner began redirecting to windows-2025-vs2026 (VS 2026 / MSVC 14.51).

Error

C:...\include\experimental\coroutine(37,1): error C2338: static_assert failed:
'STL1011: <experimental/coroutine>, <experimental/generator>, and <experimental/resumable>
are deprecated by Microsoft and will be REMOVED SOON. They are superseded by C++20
and C++23 .'
[...\plugins\permission_handler_windows\permission_handler_windows_plugin.vcxproj]

Root cause

permission_handler_windows (pulled in via permission_handler in example/pubspec.yaml) still uses <experimental/coroutine>. MSVC 14.51 in VS 2026 removed this
header entirely — it is a hard compilation error, not a warning.

This is unrelated to SDK code. It only affects the example app's Windows build in CI.

Affected runs

First encountered while investigating the Windows failure on PR #1094.

Reproducible on any PR after GitHub's runner migration. First confirmed failing run: #26249424531
(https://github.com/livekit/client-sdk-flutter/actions/runs/26249424531) (May 21, 2026) — Windows-only failure, all other platforms green.

[hiroshihorie]

Thanks for the heads up! This should be fixed by #1099 (55295de). I verified the latest main Build run is green, including Windows: https://github.com/livekit/client-sdk-flutter/actions/runs/26875726699/job/79262336261

Closing this out unless it comes back.