fix: hold Auto Refresh when Editor starts unfocused (external scene dialog/crash)

[hatayama]

Summary

• Background / never-focused Editor startup now arms DisallowAutoRefresh immediately (not only on focusChanged(false))
• Throttled update reconcile keeps focus ↔ held flag aligned; kCodeReload failures log and retry via reconcile (no delayCall retry chains)
• SessionState held flag is set/cleared only after Disallow/Allow succeed

User Impact

• Before: uloop launch in the background never fired focus-lost, so Auto Refresh stayed enabled. External Scene edits (e.g. git discard) then hit Unity’s native EditorSceneManager::HandleOpenScenesChangeOnDisk path → reload/ignore dialog, and in at least one local run a native SIGSEGV that killed the whole Editor
• After: unfocused startup holds Auto Refresh; focus return uses the existing quiet resolve path instead of the native dialog/crash path
• Out of scope (approved): discard while Unity stays focused (②) — mitigated only by reconcile + compile-time ResolveForCompile

Real-world crash evidence (pre-fix)

~/Library/Logs/Unity/Editor-prev.log (~22:27 session), after loading RaycastAnnotationPerspectiveDemoScene:

Native Crash Reporting
Got a segv while executing native code.
...
EditorSceneManager::HandleOpenScenesChangeOnDisk
EditorSceneManager::OnApplicationTick
...
EditorSceneManager::ReloadScene

This is the native external-scene-change path this PR bypasses by holding Auto Refresh until uloop can resolve quietly.

Design choices (from approved answers)

• Retry strategy: no delayCall chains — catch logs + leave unheld; update reconcile retries
• try-catch: Disallow/Allow boundary only (hatayama-approved); always logs; never swallows
• Idempotent Hold covered by pure C# tests

Verification

• uloop compile — 0 errors / 0 warnings
• uloop run-tests filter ExternalSceneChangeResolverTests — 23 passed (incl. vibe hold log tests)
• Manual clean gate: quit → CLI launch unfocused → held probe focused=False;held=True → discard → first focus → no dialog / no crash
  • Evidence: /tmp/claude-shared/pr-5-2-clean-gate-result.md (+ vibe timeline + Editor-prev.log Loaded scene before Refresh)
  • Post-fix held probe = ODE snippet reading EditorApplication.isFocused + SessionState ...AutoRefreshHeld; proves hold armed before discard/focus (not dialog absence alone)
• Manual: focused discard (②) still may dialog — expected out of scope (approved)
• ULOOP_DEBUG VibeLogger events on hold/focus/resolve/reconcile-repair (observability for gate correlation)

Test plan

• CI green on this PR
• Clean gate on patched build (see Verification)
• Domain reload: held re-armed after unfocused compile path (vibe hold_armed at launch; no permanent Disallow desync observed)

Made with Cursor

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 0be17622-7350-4618-9127-c97b59ac24a6

📥 Commits

Reviewing files that changed from the base of the PR and between 8cdb54a and bf2aa9a.

📒 Files selected for processing (3)

• Assets/Tests/Editor/ExternalSceneChangeResolverTests.cs
• Packages/src/Editor/FirstPartyTools/Compile/ExternalAssetFocusReturnService.cs
• Packages/src/Editor/FirstPartyTools/Compile/ExternalSceneChangeTracker.cs

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📝 Walkthrough

Walkthrough

The focus return service now guards Unity auto-refresh hold and release operations, logs failures, and exposes focus reconciliation methods. The scene tracker performs throttled reconciliation during editor updates, handles initially unfocused startup states, and records richer focus-return diagnostics. Tests cover idempotence, retries, release ordering, and exceptions.

Changes

Focus-aware auto-refresh handling

Layer / File(s)	Summary
Guarded focus and auto-refresh transitions Packages/src/Editor/FirstPartyTools/Compile/ExternalAssetFocusReturnService.cs, Assets/Tests/Editor/ExternalSceneChangeResolverTests.cs	The service adds warning injection, focus reconciliation methods, guarded auto-refresh operations, and held-state preservation across failures. Tests cover idempotent holding, retry behavior, release ordering, vibe logs, and warning messages.
Periodic focus reconciliation Packages/src/Editor/FirstPartyTools/Compile/ExternalSceneChangeTracker.cs	The tracker throttles update-based reconciliation, snapshots scene state during initialization, and immediately applies the unfocused hold behavior.
Focus-return diagnostics Packages/src/Editor/FirstPartyTools/Compile/ExternalSceneChangeTracker.cs	Focus changes and focus-return resolution now log auto-refresh state and per-scene fingerprint differences, including early-exit and completion data.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Sequence Diagram(s)

sequenceDiagram
  participant EditorApplication
  participant ExternalSceneChangeTracker
  participant ExternalAssetFocusReturnService
  participant UnityAutoRefresh
  EditorApplication->>ExternalSceneChangeTracker: invoke throttled update callback
  ExternalSceneChangeTracker->>ExternalAssetFocusReturnService: reconcile hold with focus
  ExternalAssetFocusReturnService->>UnityAutoRefresh: disallow or allow auto-refresh

Loading

Possibly related PRs

• hatayama/unity-cli-loop#1447: Extends the same focus-return workflow and auto-refresh hold/release behavior.
• hatayama/unity-cli-loop#1639: Introduces related focus-return and auto-refresh handling in the same service and tracker classes.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly summarizes the main change: holding Auto Refresh when the Editor starts unfocused.
Description check	✅ Passed	The description is directly related to the changeset and explains the startup, reconcile, and retry behavior.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/external-scene-unfocused-hold

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[hatayama]

LGTM (reviewed by Fable on behalf of the review flow; same-account approval unavailable).

Reviewed the full 345-line diff plus the observability commit bf2aa9a:

• All 3 approved design constraints hold: no delayCall retry chains (reconcile-only retry), SessionState held flag set/cleared only after Disallow/Allow actually succeed, throttled + idempotent update reconcile (0.5s, no-op when aligned).
• try-catch stays within the approved Disallow/Allow boundary, always logs, never swallows.
• VibeLogger instrumentation is ULOOP_DEBUG-gated, injected on the service so pure C# tests stay logger-free, and reconcile logs only on actual repair.
• Clean machine gate PASS with a non-blind held probe (focused=False, held=True before discard), vibe timeline hold_armed -> focus_changed -> resolve (fingerprint 63231 -> 63226) -> hold_released, no native dialog window, and no Asset Pipeline Refresh between discard and the quiet scene reload.

Follow-ups recorded in group5 umbrella notes: warning backoff if Disallow persistently fails, narrowing catch(Exception) once the real exception type is confirmed, and the group-3 residual (DynamicCodeExecutionScheduler slot stuck across domain reload with an idle Roslyn worker).