ci(next): check-concurrency refuses a generic main-actor class with no nonisolated deinit (the #23050 Release crash) by teamleaderleo · Pull Request #23361 · manaflow-ai/cmux

teamleaderleo · 2026-10-21T11:50:41Z

Summary

A crash-class rule so #23050's Release-compile crash can't come back (coord-deputy, 2026-10-21).

scripts/cmux-next/check-concurrency.sh: in a uiSwiftSettings target (main actor by default), a generic class must declare nonisolated deinit. Without one its implicit deinit is isolated, and the Release compile's optimizer crashes on it (EarlyPerfInliner on FirstMouseHostingView's deinit, swift-frontend 6.3, macOS 14 target). cmux NEXT browser: Downloads popup under its toolbar button, draggable rows; Chromium's bubble off #23050 (7d2ee97) added that class, every Release compile failed with compiler crash while optimizing 'deinit' until cmux-next: the Release compile no longer crashes on FirstMouseHostingView's deinit #23233 (230cc72) added nonisolated deinit {}, and fix(cmux-next): Release compile crash on main-actor generic class deinits (macOS 14 target) #20408 fixed the same crash before. A reviewed // concurrency-allow: <why> escapes the rule, like the file's other rules.
It is a crash-class rule, so CI's crash-class job (cmux-next-crash-class.yml) blocks on it, and the pre-push gate and the cmux-next checks job run it with the rest of the file.
tests/test_check_concurrency_generic_deinit.py runs the script on a fixture package with a UI and a non-UI target. Cases: cmux NEXT browser: Downloads popup under its toolbar button, draggable rows; Chromium's bubble off #23050's exact shape, red; with nonisolated deinit, green; in a non-UI target, green; an inner type's deinit doesn't count, red; the reviewed escape, green. The crash-class workflow runs it.

Out of scope: generic classes in non-UI targets

These 6 have no nonisolated deinit and sit in targets that aren't main actor by default, so the rule leaves them alone (base 4a6ef5b):

CmuxNextCompat/Mutex.swift:44 LockedStorage<Value: ~Copyable>
CmuxNextCompat/ObservedItems.swift:5 @MainActor public final class ObservedItems<Model, Item>
CmuxNextCompat/ObservedMap.swift:15 ObservedMap<Key, Value>
CmuxNextControl/Concurrency/ControlDeadline.swift:44 Race<T>
CmuxNextServerHelper/ServerHelperDeadline.swift:44 Race<T>
CmuxNextWakeups/FirstOutcome.swift:6 FirstOutcome<Value>

(My first count to coord-deputy said 7; it is 6.) ObservedItems is explicitly @MainActor but lives in CmuxNextCompat, a non-UI target, so it's outside the rule's stated scope. The 5 generic classes in UI targets already declare nonisolated deinit: ImmediateRun, FirstMouseHostingView, CEFReplyWaiters, and the Once in BrowserHistoryWriter and in PageCallDeadline.

Testing

The rule on the real tree, CHECK_CONCURRENCY_ONLY=crash-class scripts/cmux-next/check-concurrency.sh:
- red with BrowserDownloadsPopup.swift from 7d2ee97 (cmux NEXT browser: Downloads popup under its toolbar button, draggable rows; Chromium's bubble off #23050): Sources/CmuxNextApp/Handlers/BrowserDownloadsPopup.swift:459: generic main-actor class with no nonisolated deinit, exit 1.
- green on base 4a6ef5b (check-concurrency: ok), and the full check (no CHECK_CONCURRENCY_ONLY) is green too.
The fixture test: red on 8b30fd2 (test only) and green on the head, both in the crash-class job.

Observed / Not run

Observed: the two script runs above.
Not run here: the fixture test itself (running test files is blocked on this Mac); CI's crash-class job runs it on both commits.

Changelog

none

Agent session: cosmic-gray

🤖 Generated with Claude Code

^{Need help on this PR? Tag @codesmith-bot with what you need.}

Summary by cubic

Adds a crash-class rule to check-concurrency.sh so #23050's Release-compile crash can't come back: a generic main-actor class in a UI target must declare nonisolated deinit, since its implicit isolated deinit crashes the Release optimizer (fixed in #23233, previously #20408). A reviewed // concurrency-allow: escapes the rule, and non-UI targets stay out of scope.

Adds a fixture test covering the cmux NEXT browser: Downloads popup under its toolbar button, draggable rows; Chromium's bubble off #23050 shape (red), the fix (green), non-UI targets (green), inner-type deinits (red), braces in string literals (green), and the escape (green).
Runs the test from the crash-class CI job and registers it in tests/test-execution.toml.

^{Written for commit d0fef77. Summary will update on new commits.}

…onisolated deinit (red) #23050's FirstMouseHostingView, a generic NSHostingView subclass in a uiSwiftSettings target, had an implicit isolated deinit that crashed the Release compile's optimizer (fixed in #23233). This fixture test expects check-concurrency.sh to refuse that shape; the rule comes next. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Agent-Session: https://cmux.com/deeplink/agent?harness=claude&session=01a15ba2-4ce2-7e02-8fa2-5cd34f7648b1&host=cosmic-gray

teamleaderleo · 2026-10-21T11:50:52Z

Owned by claude-sr2/pane-toolbar on cosmic-gray · session

…eric-deinit-guard # Conflicts: # tests/test-execution.toml

github-actions · 2026-10-21T11:53:09Z

cmux status _{(one comment, edited in place; each line is updated by the job that owns it)}

Review d0fef77: HQ feed card · gallery before/after runs · checks

App of this head (app.zip, kept 1 day)

gh workflow run reload-build.yml -R manaflow-ai/cmux --ref feat-cmux-next -f tag=pr23361 -f ref=cmux/generic-deinit-guard -f platform=macos -f backend_mode=local

red: cmux-next checks (god files, concurrency, crash safety, l10n); base red: the same failure on the base bc5becd; does not block

blacksmith-sh · 2026-10-21T11:53:40Z

Found 6 test failures on Blacksmith runners:

Failures

Test	View Logs
`/tmp/tmpmn_gr4ja/summary-missing.json (live):/summary-missing.json (live):`	View Logs
`/tmp/tmpolm83lms/summary-fail.json (live):/summary-fail.json (live):`	View Logs
`[new_workspaces] debug.new_workspace timed 0 of 50 new workspace rows/` `[new_workspaces] debug.new_workspace timed 0 of 50 new workspace rows`	View Logs
`[new_workspaces] the window draws no frames/[new_workspaces] the window draws no frames`	View Logs
`[tabs] debug.tab_switch timed 0 of 40 switches/` `[tabs] debug.tab_switch timed 0 of 40 switches`	View Logs
`[tabs] the window draws no frames/[tabs] the window draws no frames`	View Logs

^{Need help on this PR? Tag @codesmith-bot with what you need.}

…o nonisolated deinit In a uiSwiftSettings target a generic class's implicit deinit is isolated, and the Release compile's optimizer crashes on it (EarlyPerfInliner, swift-frontend 6.3, macOS 14 target): #23050's FirstMouseHostingView broke every Release compile until #23233, the same crash #20408 fixed before. The crash-class rule now requires `nonisolated deinit` there (a reviewed `// concurrency-allow:` escapes it). Non-UI targets stay out of scope. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Agent-Session: https://cmux.com/deeplink/agent?harness=claude&session=01a15ba2-4ce2-7e02-8fa2-5cd34f7648b1&host=cosmic-gray

cursor · 2026-10-21T11:54:18Z

Bugbot needs on-demand usage enabled

Bugbot uses usage-based billing for this team and requires on-demand usage to be enabled.

A team admin can enable on-demand usage in the Cursor dashboard.

…eric-deinit-guard

…te; braces in strings don't end a class Base registered tests/test_crash_class_fast_gate.py (#23352) after the pre-commit hook had registered it on this branch, so keep base's entry only. Review: declares_nonisolated_deinit counted a "}" in a string literal; it now scans main_actor_scope.strip(line), and the header names the rule. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Agent-Session: https://cmux.com/deeplink/agent?harness=claude&session=01a15ba2-4ce2-7e02-8fa2-5cd34f7648b1&host=cosmic-gray

teamleaderleo · 2026-10-21T12:01:26Z

Bead cx-144pj created for this PR by the cmux coordinator.

…r names it Review: declares_nonisolated_deinit counted a "}" in a string literal and ended the class before its deinit. Scan main_actor_scope.strip(line), as the scope scan does. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Agent-Session: https://cmux.com/deeplink/agent?harness=claude&session=01a15ba2-4ce2-7e02-8fa2-5cd34f7648b1&host=cosmic-gray

…eric-deinit-guard

cursor · 2026-10-21T13:25:15Z

Bugbot needs on-demand usage enabled

Bugbot uses usage-based billing for this team and requires on-demand usage to be enabled.

A team admin can enable on-demand usage in the Cursor dashboard.

teamleaderleo · 2026-10-21T13:33:42Z

cmux-next guards / defaults-snapshot is red on 15 of 15 fresh feat-cmux-next PR heads in the last 2:00:00, so it is most likely a base red, not this PR's. The base-reds lane has it; a base merge picks up the fix once it lands.

github-actions · 2026-10-21T17:05:24Z

Shipped in:

cmux NEXT nightly 1.0.0-nightly.3963471158401 (799a94eff3)
cmux NEXT nightly 1.0.0-nightly.3963634661701 (cf187cf389)

teamleaderleo requested a review from lawrencecchen as a code owner October 21, 2026 11:50

teamleaderleo added the risk:low Risk tier (docs/ci/risk-tiers.md) label Oct 21, 2026

Merge commit 'f90fbd9b7db9e7f251464150a8deded4cb4c89e9' into cmux/gen…

db4b66e

…eric-deinit-guard # Conflicts: # tests/test-execution.toml

mikelbai2 and others added 2 commits October 21, 2026 04:59

Merge commit 'c911e6c57bef3fcf784424b4ba5c5fdae0573ac8' into cmux/gen…

67904a6

…eric-deinit-guard

mikelbai2 and others added 2 commits October 21, 2026 05:01

Merge commit 'bc5becdb68752942cf4e5653b390d9ae641bb183' into cmux/gen…

d0fef77

…eric-deinit-guard

teamleaderleo merged commit 8edc2c9 into feat-cmux-next Oct 21, 2026

teamleaderleo deleted the cmux/generic-deinit-guard branch October 21, 2026 15:28

Navigation Menu

Repository navigation

ci(next): check-concurrency refuses a generic main-actor class with no nonisolated deinit (the #23050 Release crash) - #23361

ci(next): check-concurrency refuses a generic main-actor class with no nonisolated deinit (the #23050 Release crash)#23361
teamleaderleo merged 7 commits into
feat-cmux-nextfrom
cmux/generic-deinit-guard

teamleaderleo commented Oct 21, 2026 •

edited by cubic-dev-ai Bot

Loading

Uh oh!

teamleaderleo commented Oct 21, 2026

Uh oh!

github-actions Bot commented Oct 21, 2026 •

edited

Loading

Uh oh!

blacksmith-sh Bot commented Oct 21, 2026 •

edited

Loading

Uh oh!

cursor Bot commented Oct 21, 2026

Uh oh!

teamleaderleo commented Oct 21, 2026

Uh oh!

cursor Bot commented Oct 21, 2026

Uh oh!

teamleaderleo commented Oct 21, 2026

Uh oh!

github-actions Bot commented Oct 21, 2026 •

edited

Loading

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Conversation

teamleaderleo commented Oct 21, 2026 • edited by cubic-dev-ai Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Out of scope: generic classes in non-UI targets

Testing

Observed / Not run

Changelog

Summary by cubic

Uh oh!

teamleaderleo commented Oct 21, 2026

Uh oh!

github-actions Bot commented Oct 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

blacksmith-sh Bot commented Oct 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Failures

Uh oh!

cursor Bot commented Oct 21, 2026

Bugbot needs on-demand usage enabled

Uh oh!

teamleaderleo commented Oct 21, 2026

Uh oh!

cursor Bot commented Oct 21, 2026

Bugbot needs on-demand usage enabled

Uh oh!

teamleaderleo commented Oct 21, 2026

Uh oh!

github-actions Bot commented Oct 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

teamleaderleo commented Oct 21, 2026 •

edited by cubic-dev-ai Bot

Loading

github-actions Bot commented Oct 21, 2026 •

edited

Loading

blacksmith-sh Bot commented Oct 21, 2026 •

edited

Loading

github-actions Bot commented Oct 21, 2026 •

edited

Loading