[yordis]

• When the desktop dev app dies without taking its backend down, the backend keeps the T3 home ownership lock, so every later mise dev:desktop fails with ServerAlreadyRunningError until someone finds and kills the process by hand.
• The runner already owns its checkout and cleans up its stale Electron apps, but the backend escaped that cleanup, so a hung or orphaned one blocked development indefinitely.

[cursor]

PR Summary

Low Risk
Changes are limited to the desktop dev runner’s process cleanup on non-Windows hosts; no production runtime or auth/data paths are affected.

Overview
Fixes mise dev:desktop getting stuck on ServerAlreadyRunningError when Electron exits but the spawned server process keeps the T3 home lock.

The dev runner now finds checkout-specific orphaned backends via a new devBackendPattern (matching server/dist/bin.mjs --bootstrap-fd) and stops them with SIGTERM, polling up to 4s then SIGKILL. Stale Electron cleanup is centralized in devAppPattern. Backend cleanup runs at startup, after stopApp, and when there is no live app (e.g. after a crash). Tests cover pattern scoping so only this checkout’s backend is matched.

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Review configuration:

Run configuration

• Source mode: Auto
• Repository: TrogonStack/t3code
• Branch: yordis/fix-desktop-dev-reclaim-orphan-backend
• File: .coderabbit.config.ts
• Commit: 09db314
• Layers: Repository TS config
• Review profile: CHILL
• Plan: Advanced
• Run ID: 8feb3db0-e54a-462a-89d8-9a8eeb622106

Commits

Reviewing files that changed from the base of the PR and between 840e212 and 09db314.

Files selected for processing: 3

• apps/desktop/scripts/dev-electron.mjs
• apps/desktop/scripts/dev-runner-guards.test.mjs
• apps/desktop/scripts/electron-launcher.test.mjs

Walkthrough

The development runner now uses checkout-specific patterns to match Electron app and backend processes. It cleans up stale backends during startup and app shutdown. On non-Windows platforms, cleanup sends SIGTERM, polls for up to four seconds, and sends SIGKILL if a matching process remains.

Changes: Development process cleanup

Layer / File(s)	Summary
Checkout-specific process patterns apps/desktop/scripts/dev-runner-guards.mjs, apps/desktop/scripts/dev-runner-guards.test.mjs	Adds patterns for the checkout’s Electron app and spawned backend. Tests check literal path matching and distinguish the Electron-launched backend from other processes.
Stale process cleanup apps/desktop/scripts/dev-electron.mjs	Uses the app pattern for stale app cleanup and adds backend cleanup at startup and after app teardown. On non-Windows platforms, backend cleanup sends SIGTERM, polls, then sends SIGKILL if needed.

Priority: Normal

Estimated code review effort: 2 (Simple) | ~12 minutes

Change: Bug fix

Possibly related PRs

• TrogonStack/t3code#140: Prevents a second development session from starting when a T3 home ownership lock is active; this PR handles stale backends that retain that lock.

Suggested reviewers: saphid, juliusmarminge

Merge Risk: Moderate · up to 840e2

An automatic desktop restart can fail because the previous backend still holds the home lock. Fix cleanup on the unexpected-exit path before merging.

Pre-merge checks: 3 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Description check		The description explains the problem and failure mode, but it does not include the required Change, Scope and approval, or Verification sections.	Add the required sections. Describe the implementation, provide the issue or maintainer approval rationale, and document focused tests or manual checks with observed results and any limitations.

Passed checks: 3 passed

Check name	Status	Explanation
Title check		The title clearly and concisely identifies the desktop development runner fix for orphaned backends that retain the T3 home lock.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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Actionable comments posted: 1

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• 🪄 Fix comments: Fix CodeRabbit comments on this PR

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Inline comments:
Review comments at @apps/desktop/scripts/dev-electron.mjs:
- Line 251: Update the !app path in stopApp to run stopStaleDevBackends before
startApp, so backend cleanup still occurs when currentApp is null.

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Review info

Run configuration

• Source mode: Auto
• Repository: TrogonStack/t3code
• Branch: yordis/fix-desktop-dev-reclaim-orphan-backend
• File: .coderabbit.config.ts
• Commit: 840e212
• Layers: Repository TS config
• Review profile: CHILL
• Plan: Advanced
• Run ID: 6fbfe16b-b1da-4f4e-9128-ca5cdade7efb

Commits

Reviewing files that changed from the base of the PR and between 0034d7e and 840e212.

Files selected for processing: 3

• apps/desktop/scripts/dev-electron.mjs
• apps/desktop/scripts/dev-runner-guards.mjs
• apps/desktop/scripts/dev-runner-guards.test.mjs

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