Refuse breeze start dev mode when UI development ports are already in use - #71241
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Andrushika wants to merge 1 commit into
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Refuse breeze start dev mode when UI development ports are already in use#71241Andrushika wants to merge 1 commit into
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Starting dev mode while an older Vite server owns the required ports can leave Breeze serving assets from another worktree. Failing early makes the conflict visible instead of starting a mismatched environment.
Andrushika
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August 6, 2026 14:43
boring-cyborg
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backport-to-v3-3-test
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August 6, 2026 17:42
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August 6, 2026 17:42
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Why
I was using Git worktrees and accidentally ran
breeze start-airflow --dev-modefrom a second worktree. Breeze showed no warning, but the browser only showed a blank page.Root cause: the old Vite process still owned port 5173 or 5174, so the new Vite process exited silently because of
--strictPortwhile Breeze continued starting Airflow and the browser kept loading assets from the old Vite server.What
Check both ports before starting the background UI dev hook, and fail with a clear message when either port is in use. This only applies to dev asset compilation; regular UI asset builds are unchanged.
This PR only handles port conflicts that already exist when
run_compile_ui_assetsstarts.compile_ui_assets_dev.pystill does not keep thePopenhandles, so it cannot detect a Vite process that exits later. I plan to handle process supervision in a follow-up PR.Was generative AI tooling used to co-author this PR?
Generated-by: Codex (GPT-5) and Claude Code (Fable 5) following the guidelines