cmux-next: FolderChanges.events() returns once its watches are registered by teamleaderleo · Pull Request #26517 · manaflow-ai/cmux

teamleaderleo · 2026-10-28T02:12:59Z

Fix-forward for #26320 (squash 39d216b), from its post-landing review, which answered FIX:

The startup race remains — FolderChanges.swift:44,87. arm() calls source.resume(), which does not guarantee registration has completed. dispatch_source(3) explicitly documents that events during this delay are missed. A write after events() returns can therefore still disappear. Establish readiness through setRegistrationHandler before promising the watch is armed; rearming needs the same guarantee.

The test remains timing-dependent — FolderChangesTests.swift:27–32. [...] Add a deterministic readiness test with delayed registration.

What changes

FolderChanges.events() is now async. arm() gives every dispatch source a registration handler and waits for each one before it returns, so a change made after events() returns is always delivered. The wait ends early if the calling task is cancelled, so a cancelled caller never hangs.
When the watch has to move, the loop waits for the new watches to register before it cancels the old ones and yields the element, so re-arming has the same guarantee.
BackdropCatalogStore (the only production caller) awaits events().
If the caller is cancelled during that wait, events() cancels the watch and returns a finished stream. The detached loop never holds descriptors for a caller that will not iterate.
New test FolderChangesTests.eventsReturnsOnlyOnceTheWatchesAreRegistered. An internal init sets the queue the sources target. The test holds that queue suspended so no registration handler can run, and starts events() with Task.immediate, so it runs synchronously up to its first suspension. It checks two things: events() returns only after the queue is resumed (from an ordered step log), and a write made the moment it returns produces an element. There is no sleep. With the fix the test cannot fail, however the threads are scheduled. Without the wait, events() has no suspension point and returns before the test resumes the queue, so the test fails every time.
Kept from the earlier review: there are no new file descriptors or sources. Cancel handlers still close every fd, and cancellation still reaches armed.cancel().

No capture: no visible UI change; this only changes when the folder watch behind the wallpaper catalog reports that it is ready.

Risk

Low. The change is contained to the folder watch behind the wallpaper catalog. events() now waits for kernel registration before returning, which is sub-millisecond.

Verification

Fleet runs pending; this section is updated with their results.

Agent session: agent session

🤖 Generated with Claude Code

…ered Post-landing review of #26320: arm() resumed each DispatchSource and returned, but resume() only schedules the kernel registration, and dispatch_source(3) says events before it completes are missed, so a write right after events() returned could still be lost. arm() now waits for every source's registration handler (events() is async), and the loop re-arms the same way before it yields. A new test holds the watches' queue suspended and checks events() returns only after it is let go, and that a write the moment it returns is seen. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Agent-Session: https://cmux.com/deeplink/agent?id=aid-cc8bff1c3ddb4ec353c5

teamleaderleo · 2026-10-28T02:13:08Z

Owned by an agent session · session

github-actions · 2026-10-28T02:13:12Z

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

Review 366a8e7: 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=pr26517 -f ref=ib/folderchanges-registration -f platform=macos -f backend_mode=local

red: cmux-next checks (god files, concurrency, crash safety, l10n); NEW: green on the base 8acb82a; do not merge until green; see lane-rules

…terministic Review of the fix: the 200 ms sleep did not guarantee the task ran while the queue was held, so a regression could still pass. Task.immediate runs events() on the test's thread until its first suspension, which with the fix is the wait for registration and without it is never reached before it returns. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Agent-Session: https://cmux.com/deeplink/agent?id=aid-cc8bff1c3ddb4ec353c5

blacksmith-sh · 2026-10-28T02:23:01Z

Found 7 test failures on Blacksmith runners:

Failures

Test	View Logs
`/tmp/tmpdxav8fkh/summary-missing.json (live):/summary-missing.json (live):`	View Logs
`/tmp/tmptu6w8ae3/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
`convention violations found (ERROR lines above)./` `convention violations found (ERROR lines above).`	View Logs

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

teamleaderleo · 2026-10-28T02:26:43Z

Bead cx-0ks52i created for this PR by the cmux coordinator.

… stream Review of the fix: a cancelled caller that never iterates would leave the detached loop holding the watch and its descriptors. events() now cancels the watch and finishes the stream instead of starting the loop. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Agent-Session: https://cmux.com/deeplink/agent?id=aid-cc8bff1c3ddb4ec353c5

teamleaderleo · 2026-10-28T03:49:23Z

Review (codex gpt-6-astra high, next-review): SHIP at 366a8e7

No blocking findings. Reviewed registration readiness, rearming, cancellation, and the updated caller and tests. Validation was limited to the supplied files; tests were not run.

teamleaderleo · 2026-10-28T18:58:34Z

Orphaned: no activity for 15 h, and no lane holds a lease on it. Adopted by the orphan sweep: merged feat-cmux-next in at ce569c4. A later pass queues it for the merge hub if it is reviewed, small and red only on base reds.

teamleaderleo · 2026-10-28T20:31:16Z

Review (codex gpt-6-astra high, next-review): SHIP at ce569c4

No blocking findings.

A newer verdict blocks 61e571c (no independent SHIP at the head).

teamleaderleo · 2026-10-29T22:54:15Z

Review (codex gpt-6-astra high, next-review): SHIP at 61e571c

No blocking findings.

Reviewed the supplied diff and changed files. Tests were not run; access to additional repository code was blocked by the tool approval policy.

cmux-bot

cmux-bot approves 61e571c: an independent review passed this exact head (next-review receipt by teamleaderleo). A push needs a new review; a later BLOCK at this head dismisses this approval.

github-actions · 2026-10-29T23:52:41Z

The feat-cmux-next push run https://github.com/manaflow-ai/cmux/actions/runs/40975388675 at 43303f7 failed: cmux-next checks (god files, concurrency, crash safety, l10n), cmux-next fleet Release compile.
Those jobs last passed at 94e3fa5. This pull request is one of 3 merged since: #26517, #27679, #26082.
If the failure is in your change, fix forward on feat-cmux-next. Pull requests run only the tiers their paths reach (docs/ci/cmux-next-tiers.md); label a batch PR full-ci to run them all before merging.

github-actions · 2026-10-29T23:54:08Z

The feat-cmux-next push run https://github.com/manaflow-ai/cmux/actions/runs/40975576275 at 60a6a31 failed: cmux-next checks (god files, concurrency, crash safety, l10n), cmux-next fleet Release compile.
Those jobs last passed at 94e3fa5. This pull request is one of 4 merged since: #26517, #27679, #26082, #27682.
If the failure is in your change, fix forward on feat-cmux-next. Pull requests run only the tiers their paths reach (docs/ci/cmux-next-tiers.md); label a batch PR full-ci to run them all before merging.

github-actions · 2026-10-30T01:04:15Z

The feat-cmux-next push run https://github.com/manaflow-ai/cmux/actions/runs/40977234399 at 817e10c failed: cmux-next checks (god files, concurrency, crash safety, l10n), cmux-next fleet Release compile.
Those jobs last passed at 94e3fa5. This pull request is one of 4 merged since: #26517, #26082, #25151, #25420.
If the failure is in your change, fix forward on feat-cmux-next. Pull requests run only the tiers their paths reach (docs/ci/cmux-next-tiers.md); label a batch PR full-ci to run them all before merging.

…ld fix) (#27758) #26517 made FolderChanges.events() async (it returns once its watches are registered); #27223, which landed an hour before it, calls it from the synchronous MachineConsentChanges.events(armed:). Together they stop CmuxNextApp from compiling (JoinConsent+App.swift:222: 'async' call in a function that does not support concurrency; fleet job 549a2bfa50c634b6131799d8). MachineConsentChanges.events(armed:) is async now and awaits it, so the folder watch is registered before the file watches and the armed handshake, as its comment already promised; its callers (the model's watch task and JoinConsentTests) await it. Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

…atch #26517 made FolderChanges.events() async (it now returns once its watches are registered). #27223 landed alongside it with MachineConsentChanges calling events() synchronously, so feat-cmux-next stopped compiling in Release from 00d6d54 on (cmux-next/compile red on every landing since), and no NEXT nightly can build a newer commit. MachineConsentChanges.events(armed:) is now async and awaits the folder's registration before arming the files, which keeps its documented order; its app caller and the two tests await it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Agent-Session: https://cmux.com/deeplink/agent?id=aid-fb75b7af9902231028aa

github-actions · 2026-10-30T03:31:10Z

Shipped in:

cmux NEXT nightly 1.0.0-nightly.4099263986101 (1816f75ed1)

github-actions · 2026-10-30T03:32:56Z

Shipped in:

cmux NEXT nightly 1.0.0-nightly.4099184203401 (0b45ce8ec3)
cmux NEXT nightly 1.0.0-nightly.4099558415201 (c0331557f5)

teamleaderleo had a problem deploying to ci-routing-agent October 28, 2026 02:13 — with GitHub Actions Error

github-actions Bot added the risk:normal Risk tier (docs/ci/risk-tiers.md) label Oct 28, 2026

teamleaderleo temporarily deployed to ci-routing-agent October 28, 2026 02:17 — with GitHub Actions Inactive

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teamleaderleo temporarily deployed to ci-routing-agent October 28, 2026 02:31 — with GitHub Actions Inactive

teamleaderleo temporarily deployed to ci-routing-agent October 28, 2026 02:33 — with GitHub Actions Inactive

Merge feat-cmux-next into ib/folderchanges-registration

ce569c4

teamleaderleo temporarily deployed to ci-routing-agent October 28, 2026 18:58 — with GitHub Actions Inactive

teamleaderleo temporarily deployed to ci-routing-agent October 28, 2026 19:07 — with GitHub Actions Inactive

Merge branch 'feat-cmux-next' into ib/folderchanges-registration

fe94b96

cmux-bot Bot temporarily deployed to ci-routing-agent October 28, 2026 21:46 Inactive

cmux-bot Bot temporarily deployed to ci-routing-agent October 28, 2026 22:01 Inactive

Merge feat-cmux-next into ib/folderchanges-registration

7cc74f5

teamleaderleo temporarily deployed to ci-routing-agent October 29, 2026 10:30 — with GitHub Actions Inactive

Merge branch 'feat-cmux-next' into ib/folderchanges-registration

61e571c

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cmux-bot Bot approved these changes Oct 29, 2026

View reviewed changes

teamleaderleo merged commit 00d6d54 into feat-cmux-next Oct 29, 2026
148 of 153 checks passed

teamleaderleo deleted the ib/folderchanges-registration branch October 29, 2026 23:43

This was referenced Oct 29, 2026

ci(cmux-next): the DEV Release product receipt records the resolved Swift mode #27679

Merged

Agent chat: PR pills share the message action row #26082

Merged

github-actions Bot mentioned this pull request Oct 29, 2026

fix(tailnet): decide a failure close on the closing thread, under the fence's lock #27682

Merged

This was referenced Oct 30, 2026

fix(cmux-next): await FolderChanges.events() in the machine consent watch (base Release compile red) #27722

Closed

ci(nightly-next): build the tip at once and install its tree's attested client when the tree publishes #27531

Closed

azooz2003-bit mentioned this pull request Oct 30, 2026

cmux NEXT: await FolderChanges.events() in MachineConsentChanges (build fix) #27758

Merged

This was referenced Oct 30, 2026

cx-oy6yl: Capture update survival with nine agents and four commands #25151

Merged

cmux NEXT sidebar: drag the Chief out to remove it; a Chief just added draws before its echo (2/2 of #23933) #25420

Merged

teamleaderleo mentioned this pull request Oct 30, 2026

Agent pane: a prompt the journal could not write is not sent (Not sent, with Retry) #27735

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