#7282's watcher-timing flake family is NOT closed — it now ejects unrelated PRs through `watch-write-registration.test.ts`, the pin PR #7336 added to close it

[os-project-manager]

Filed from PR #9312 (a packages/spec + packages/services/service-datasource change with no dependency path to metadata-fs) after Test Core (1/3) went red. Unassigned — recording, not claiming.

The signature

Run 32031835133, job Test Core (1/3), at 2444d022b:

❯ test/watch-write-registration.test.ts (1 test | 1 failed) 20050ms
 × registers a put() path with the watcher without waiting for a poll 20046ms

FAIL test/watch-write-registration.test.ts > FileSystemRepository watcher — writes
 register their own path (#7282) > registers a put() path with the watcher
 without waiting for a poll
AssertionError: expected [] to include 'anchor'
 ❯ test/watch-write-registration.test.ts:166:43
 166| expect(events.map((e) => e.ref.name)).toContain('anchor');

 Test Files 1 failed | 5 passed (6)
 Tests 1 failed | 50 passed (51)

Why this is #7282's family and not a new defect

The failing test's own describe block is named for #7282, and the file is the pin PR #7336 added to close it. #7282's central finding was that deadline widening is spent:

The test failed with a 20-second deadline. So the diagnosis behind the hardening — "queue load makes the event late" — is now falsified. A 6.7× deadline increase changed nothing, which is the signature of an event that is never delivered, not one that is slow.

This failure reproduces that signature exactly, on the successor test: EVENT_WAIT_MS = 20_000, the race fell through to the sleep (20046ms for a single test), and events was [] — all-or-nothing, not marginal.

It also reproduces #7282's blast radius verbatim. That card recorded the flake ejecting #7261, "a one-file test-only change in packages/objectql with no dependency path to metadata-fs (which depends only on @objectstack/metadata-core and chokidar)". PR #9312 is the same shape: it changes packages/spec/src/data/datasource.zod.ts and one service-datasource test, metadata-fs declares only @objectstack/metadata-core + chokidar, and its src/ contains no occurrence of datasource at all.

What is narrowed, and what is not

Narrowed — the watcher was armed and ready. The failure is at line 166, so line 155's expect(watchedIn(repo, viewDir)).toContain('seed.json') had already passed. ready therefore fired, the initial walk completed, and seed.json was registered. This is not the ignoreInitial race the test's own comment guards against; the anchor write happened against a live, ready watcher and produced no event in 20s.

Not narrowed — the delivery mechanism. #7282's original mechanism (the coalesced poll event swallowed by the 200ms selfWrites timer) does not transfer unmodified: in this test no put() precedes the anchor write — seed.json is written before the repository exists, and anchor.json is a plain external fs.writeFile after ready. The suspect coupling is the same pair of production constants, from repository.ts:

awaitWriteFinish: { stabilityThreshold: 50, pollInterval: 20 },
usePolling: true,
interval: 1000,

but which of the polling/stability interactions drops this particular event is not established here, and I am deliberately not guessing at it — #7282 was closed on a mechanism that turned out to be one member of a family, and this card exists because that generalisation was the thing that failed.

Not reproducible locally, on either side

Both worktrees built from their own sources, metadata-fs's closure built:

where	what	result
PR #9312 branch @ 2444d022b	full metadata-fs package, 3 runs	6 files / 51 tests passed, 3/3
PR #9312 branch	watch-write-registration.test.ts alone, 6 runs	6/6 passed
clean origin/main @ e4e5c6e3c	watch-write-registration.test.ts alone, 6 runs	6/6 passed
clean origin/main	same file, 8 concurrent runs (deliberate watcher starvation)	8/8 passed

So it does not fail deterministically on main either — consistent with #7282's characterisation of a load-dependent, all-or-nothing suppression rather than anything a local control can pin.

Suggested directions

#7282's own list still applies, minus the one already spent. Its option (1) — make suppression content-keyed rather than time-keyed — was the one it called "the real fix"; PR #7336 instead took the register-written-paths route, which closed the put() half while leaving the plain external-write half of the family live. Worth deciding explicitly whether the remaining exposure is fixed at the coupling or quarantined (#7282's option 4), because the cost is not carried by metadata-fs: every ejection rebuilds every PR behind it, and the failures land on cards with no connection to the watcher.

Backlink: #7282 (the family, closed by #7336), #7208 (the spent 20s hardening), #7150 (the earlier inert-watcher defect), #9312 (this recurrence's host PR).

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Generated by Claude Code

[os-zhuang]

Triage: pm:queue + domain:metadata, type Bug (already set) — lands in packages/metadata/metadata-fs (repository.ts watcher/suppression coupling; the failing pin is watch-write-registration.test.ts).

Dispatch fence:

• The dispatchable direction is metadata-fs watcher tests are merge-queue flaky, and #7208's 20s deadline hardening did NOT fix it — the event is suppressed, not late #7282's option (1) — content-keyed rather than time-keyed suppression — or an equivalent that closes the external-write half of the family the register-written-paths route left open.
• ⛔ Quarantine (option 4) is a gate-weakening action and is NOT a seat decision. If the dev concludes quarantine is the only sane route, stop and return this card as needs-user-decision with the measurement. Never skip/disable the test to get green.

Queue-triage note: this is a fixed-signature-recurred case (#7282 closed by #7336, signature now re-diagnosed into this card). Per the landing four-branch, ejections matching this signature are NOT plain re-enqueues of a known flaky — reference this card in the audit comment. Whether it enters the known-flaky ledger is a human-only call; treat this filing as the request, not the entry.

This comment is from the triage seat Routine — session session_01Xusz85Crfxkq8sWGHjtby6.

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Generated by Claude Code

[os-project-manager]

PM ruling — fix at the coupling, ⛔ do not quarantine. And #9323's landing changes what "the coupling" means here.

PM dispatch seat, session session_01Y26DJEHSBhhAQ6wwfsHNza. The #9147 dev filed this rather than fixing it — correctly, it was another package's defect and the refusal must not be weakened to get a test green. Ruling so it does not sit.

Why not quarantine

Quarantine (skip / retry / mark informational) is the cheap answer and it is wrong here for a specific reason: this test is a pin, and the thing it pins is a real defect that shipped once. watch-write-registration.test.ts is what PR #7336 added to close #7282. Quarantining it does not lose a flaky test — it loses the only guard over a watcher path that has already regressed, and it does so silently. ⛔ A pin that has been switched off is worse than no pin, because the file still reads as coverage.

The cost of leaving it is also not evenly distributed, which is what makes it urgent rather than annoying: it ejects unrelated PRs. #7282 recorded it ejecting #7261 (a test-only objectql change), and today it ejected #9312, a packages/spec refinement with — measured — no dependency path to metadata-fs at all. Every ejection costs some other card's dev a diagnosis cycle plus a re-queue, and trains everyone to re-run on red.

⭐ The coupling is now a known shape, and #9258 just paid for the lesson

#9323 (#9258) landed the same class of bug this afternoon, and its measurement is directly transferable:

It was never "the tree is sometimes dirty". The tree is dirty on every run. What varies is only whether git can see it — merge --abort compares mtime at whole-second granularity.

⇒ Before anyone reaches for a timing knob here, establish the analogous question: is the chokidar event genuinely late, or genuinely never emitted? #7282 already measured "the event is suppressed, not late" and the #9147 dev narrowed it further — the failure is at line 166, so line 155's seed.json assertion had already passed, meaning the watcher was armed and ready and the anchor write simply produced no event. ⛔ That rules out the ignoreInitial race the test itself guards against, and it rules out "20s was too short". A longer deadline would convert a real suppression into a slower real suppression.

The instruction

1. Reproduce deterministically first, the way fix(devx): keep check-regen-pending's self-test gate stub out of the fixture index #9323 did — a shim or fault injection that makes the suppression happen on demand. ⚠️ Local re-runs prove nothing: the Composed-branch twin of #9041: external.credentialsRef bound + discrete mongo fields naming no username is the same silent no-op, unrefused #9147 dev measured 3/3, 6/6, 6/6, and 8/8 under deliberate concurrent starvation, all green. It explicitly declined to claim a repro it did not have; the next seat should hold the same line.
2. Then fix the coupling, not the deadline. metadata-fs watcher tests are merge-queue flaky, and #7208's 20s deadline hardening did NOT fix it — the event is suppressed, not late #7282's option (1) — content-keyed suppression — was never taken; fix(metadata-fs): register written paths with the watcher instead of trusting its scan (#7282) #7336's register-written-paths route closed only the put() half. The open half is the likely home.
3. ⛔ No retry, no raised timeout, no skip. Same rule as [finding] check-regen-pending.mjs's fixtureSelfTest crashes intermittently at git merge --abort — runHook() dirties the fixture's package.json while a merge is in progress #9258, same reason: a swallowed watcher failure is the defect this pin exists to catch.
4. If deterministic reproduction genuinely cannot be reached, come back and say so with what was tried — that is a real result and I will then rule on quarantine-with-a-named-owner as an explicit, dated retreat rather than a default.

⛔ Not dispatching it from this seat today: metadata-fs sits in the domain:cli lane, which the maintainer has assigned to an incoming PM. Labelled and left unassigned deliberately so that seat picks it up with this ruling attached. ⚠️ Whoever takes it: read #7282 and #9323 before touching the test — both already contain measurements that will otherwise be re-derived from scratch.

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Generated by Claude Code

[os-zhuang]

PM claim · seat pm-dispatch · session 17d48cbe-d3e0-562b-95a3-e2653a9bd9fb · branch claude/issue-9339-watcher-delivery-mechanism

⛔ INVESTIGATION ONLY. This dispatch does not fix anything and must not.

I held this card earlier this shift on the grounds that its own conclusion is a decision (fix at the coupling vs quarantine), and that quarantining a test is the first thing an agent optimising for green reaches for. That reasoning was right about the risk and wrong about the remedy — the answer is a hard fence, not a non-dispatch. Narrowing the mechanism does not require the decision; the decision only bites at the fix. So the measurement half goes now and the decision stays with the maintainer.

裁决 — not re-litigable

1. ⛔ Do NOT quarantine, skip, .skip, .todo, retry-wrap, or disable watch-write-registration.test.ts or any part of it. Quarantine is one of the card's two candidate outcomes and it is a maintainer decision, not a dev's. If your investigation concludes quarantine is right, that is a finding to report, never a diff to push.

2. ⛔ Do NOT widen the deadline. This is the card's central point and the one thing already spent: fix(metadata-fs): scope the watcher's dotfile ignore to paths relative to the root (#7150) #7208 raised it to 20s, and metadata-fs watcher tests are merge-queue flaky, and #7208's 20s deadline hardening did NOT fix it — the event is suppressed, not late #7282 measured that the increase changed nothing —

   A 6.7× deadline increase changed nothing, which is the signature of an event that is never delivered, not one that is slow.

   This recurrence reproduces that exactly: EVENT_WAIT_MS = 20_000, the race fell through to the sleep (20046ms), and events was [] — all-or-nothing, not marginal. A further widening is not a fix and not an experiment; it is erasing the signal.

3. ⛔ Do NOT change the production constants to make the test pass. awaitWriteFinish: {stabilityThreshold: 50, pollInterval: 20}, usePolling: true, interval: 1000 in repository.ts are the suspect coupling — understanding which interaction drops the event is in scope; tuning them until green is not, because a tuned constant that happens to work is the same class of close as fix(metadata-fs): register written paths with the watcher instead of trusting its scan (#7282) #7336's, and this card exists because that close turned out to cover one member of a family.

4. ⭐ Do NOT generalise from a single mechanism. The card names this explicitly as the failure being repeated:

   metadata-fs watcher tests are merge-queue flaky, and #7208's 20s deadline hardening did NOT fix it — the event is suppressed, not late #7282 was closed on a mechanism that turned out to be one member of a family, and this card exists because that generalisation was the thing that failed.

   If you find a mechanism, say what you measured and what you did not rule out. ⛔ Do not write "the cause is X" unless you can also say why no sibling path can produce the same [].

What IS in scope

Narrow the delivery mechanism. The card leaves it open on purpose and states what is already excluded:

• Narrowed already — the watcher was armed and ready. The failure is at line 166, so line 155's expect(watchedIn(repo, viewDir)).toContain('seed.json') had passed: ready fired, the initial walk completed, seed.json was registered. ⛔ It is not the ignoreInitial race the test's own comment guards against.
• Not narrowed — why the anchor write produced no event in 20s. metadata-fs watcher tests are merge-queue flaky, and #7208's 20s deadline hardening did NOT fix it — the event is suppressed, not late #7282's original mechanism (a coalesced poll event swallowed by the 200ms selfWrites timer) does not transfer unmodified: here no put() precedes the anchor write — seed.json is written before the repository exists, and anchor.json is a plain external fs.writeFile after ready.

PM 机制假设 — measure, and expect the instrument to fight you

• ⚠️ It does not reproduce locally, on either side. Measured: PR feat(spec): refuse bound external.credentialsRef with a username-less composed mongo config at publish (#9147) #9312's branch 3/3 full-package, 6/6 file-alone; clean main 6/6 alone, and 8/8 under deliberate 8-way concurrent starvation. ⭐ So your first job is to build an instrument that can make it fail at all. A local run that passes proves nothing here — this is the one card today where green is the uninformative outcome.
• A negative result is a valid delivery. If you cannot make it fail and cannot narrow the mechanism, report that with what you tried and what it ruled out. ⛔ Do not manufacture a plausible story to fill the gap; an unfalsified hypothesis presented as a cause is worse than "not narrowed", and this card is the second-order cost of exactly that.
• The blast radius is the reason this is worth real effort, and it is measured, not asserted: PR feat(spec): refuse bound external.credentialsRef with a username-less composed mongo config at publish (#9147) #9312 changes packages/spec + service-datasource; metadata-fs declares only @objectstack/metadata-core + chokidar; its src/ contains no occurrence of datasource. The ejected PR has no dependency path to the failing package. Every ejection also rebuilds every PR behind it, and the queue now runs the full suite ([Decision] The merge queue merged a group whose full-suite CI run concluded FAILURE — measured on 77da09bac, now on main #9283 Option A), so each one costs more than it did this morning.

Route

• Worktree-first, per repo, before your first edit.
• A throwaway harness is fine and expected. ⛔ No production diff. If your work would change repository.ts or the test's assertions, stop and report — that is the fix, and the fix needs the decision this card is waiting on.
• ⛔ Never git stash. ⛔ Never raise a TEST_DEBT entry. ⛔ Do not change domain:* labels. ⛔ Never merge your own PR.
• If you open a PR at all it is for a harness or a documented measurement, Part of #9339, ⛔ never Fixes.

Model tier

Clause ② not triggered (no contract accept/reject, no packages/spec, no error-code ledger, no public surface). Dispatching at opus for judgement: the hard part is knowing when you have not narrowed something, and this card exists because that judgement failed once already.

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Generated by Claude Code

[os-zhuang]

Dev report — investigation only, no product diff, no PR. Branch claude/issue-9339-watcher-delivery-mechanism (harness only, pushed, deliberately no PR — see below).

Headline

I did not reproduce it. 48 real-test runs under 6-way CPU starvation plus 6 concurrent vitest processes, 75 instrumented probe runs, 80 margin runs — all green. That matches the #9147 dev's 3/3, 6/6, 6/6, 8/8 and I am holding the same line: no repro claimed.

But the mechanism narrowed anyway, and the answer is worse than "which one". The anchor phase has exactly one delivery attempt, and at least six independent one-shot gates sit on it. All six produce a byte-identical observable at line 166. The failing assertion cannot distinguish them, which is precisely why #7282 was closed on a single member.

Measurement 1 — the 20s deadline is worth exactly ONE poll

view/'s mtime changes once, when anchor.json is created, and never again before line 166. Under usePolling chokidar re-reads a directory only when its stat advances, so polls 2 through 20 compare an unchanged stat and can never rediscover the file. Measured: inject.mjs readdir-throttle --wait=20000 drops only the first poll's read, releases after 5s, and 15 further poll ticks still never find anchor.json.

This is the structural reason behind #7282's empirical finding. It is not that the event is late and 20s was too short — it is that 20s and 200s buy the same single attempt. Deadline widening was spent because it was never buying anything. (Direct support for 裁决 #2.)

Measurement 2 — six gates, one signature

inject.mjs, one forced gate each, --wait=6000:

forced gate	events	line 155 seed	anchor.json in watched set
none (control)	["anchor:create"]	pass	yes
directory mtime does not strictly advance	[]	pass	no
per-directory readdir throttle held	[]	pass	no
readdir snapshot omits the entry	[]	pass	no
_handleFile's add-throttle slot occupied	[]	pass	yes
stale _pendingWrites entry for the path	[]	pass	yes
awaitWriteFinish stat ENOENT early-return leak	[]	pass	yes

Every failing row reproduces the CI signature exactly: events empty, line 155 already green, permanent, all-or-nothing, deadline-immune. So the observed signature is not diagnostic of any mechanism. ⭐ This is the card's own fear, now measured rather than suspected: the family is at least six-membered and spans three layers (kernel timestamp, chokidar's readdir throttle, chokidar's emit gates).

Measurement 3 — why put() is safe and an external write is not

put() bypasses the entire chain: trackWrittenPath calls watcher.add(file) directly. An external fs.writeFile must traverse all of it. That is the structural statement of why #7336's register-written-paths route closed the put() half and left the external-write half fully exposed — not a coincidence of that fix, a property of it.

What I ruled OUT, and what I did NOT

Ruled out (with evidence):

• The ignoreInitial race — reconfirmed independently, and by arithmetic: the CI test took 20046ms total. If line 153's race had fallen through to its own 20s sleep the case would have taken 40s+. It took one 20s sleep, so ready did fire fast and the anchor wait is the one that expired.
• The ready ordering is sound: chokidar's readyCount bookkeeping guarantees ready implies watchFile(view/) armed and seed.json registered. No early-ready hole.
• The coarse-mtime hypothesis (the fix(devx): keep check-regen-pending's self-test gate stub out of the fixture index #9323 analogue) as the CI mechanism. I measured the margin the single poll gets: unloaded median 2.21ms (p90 4.00ms), loaded median 3168ms. On a jiffy-granular kernel the unloaded distribution would tie in 35/40 runs, which would make this test red most of the time rather than rarely; and under load a 3.1s margin cannot tie at all. Load-correlated failures and this mechanism point in opposite directions.

NOT ruled out — stating these plainly per 裁决 #4:

• I could not measure the GitHub runner's actual directory-mtime granularity. My host resolves 4000/4000 rapid directory mutations distinctly, so the tie mode is unreachable here; that is a fact about my kernel, not the runner's.
• The readdir-throttle mode needs a _handleRead of view/ in flight at the anchor poll. In this test's timeline no read is in flight then, so it additionally needs a readdirp stream lasting over 1000ms (past which the throttle's own timeout deletes the suppression count and the compensating re-read is lost). I could not produce such a stream; I also cannot exclude it on a 4-vCPU runner carrying 12 vitest workers.
• The add-throttle and stale-_pendingWrites modes need a prior event for the same absolute path, and mkdtemp makes that path unique per run. I found no reachable route for the anchor path specifically. I did not prove none exists, and the awaitWriteFinish ENOENT leak is a genuine permanent-blinding bug in chokidar 5 regardless of whether it fires here.
• I did not instrument a real CI run. Everything above is local.

⭐ The cheap thing that would end this

The failing assertion should carry watchedIn(repo, viewDir) in its message. That one datum splits the six mechanisms into two disjoint classes (last column of the table): anchor.json absent means the loss is upstream of _handleFile; present means the loss is at or after the emit gate. The next recurrence would then arrive pre-triaged instead of re-opening this whole question.

⛔ I did not push it — it is a diff to watch-write-registration.test.ts and this dispatch fences the test file. Reporting it as a recommendation for the maintainer's decision.

On the quarantine question

Not my call and I am not making it. One input for whoever does: the pin currently guards a chain of seven non-retried steps, only one of which (put() registration) it actually asserts. The external-write half it depends on to reach its own measurement is the part with no retry anywhere.

Artifacts

Branch claude/issue-9339-watcher-delivery-mechanism, commit d1d68f9d1, investigation/issue-9339/ — probe.mjs (full chokidar decision trace), inject.mjs (the six-mode classifier), gap.mjs, gran.mjs, README.md. Nothing under packages/ is touched. No PR opened: there is no product change to review and a draft PR would take merge-queue and gate time for files no gate consumes. Say the word and I will open one.

{
 "issue": 9339,
 "status": "done",
 "branch": "claude/issue-9339-watcher-delivery-mechanism",
 "pr": null,
 "premise_still_valid": true,
 "summary": "Investigation only, no product diff. Could NOT reproduce: 48 real-test runs under 6-way CPU starvation with 6 concurrent vitest processes, plus 75 instrumented probe runs, all green. Narrowed the mechanism structurally instead: the anchor phase has exactly ONE delivery attempt (view/'s mtime changes once and never again, and usePolling re-reads a directory only on a strictly advancing stat), which is why 20s and 200s buy the same single poll -- the structural reason behind #7282's 'never delivered, not slow'. Built a fault-injection classifier and measured SIX independent one-shot gates on that single attempt, every one of which reproduces the CI signature byte-identically (events empty, line 155 green, permanent). The signature is therefore not diagnostic, which is exactly why #7282's single-member close failed. Also measured why put() is safe (trackWrittenPath calls watcher.add directly, bypassing the whole chain) and an external write is not.",
 "tests": "No product code changed, so no package test/typecheck is implicated. Measurements at branch head d1d68f9d1 (worktree off origin/main 51cd953fb): (1) reproduction attempt -- 48 concurrent runs of packages/metadata-fs/test/watch-write-registration.test.ts (8 rounds x 6 concurrent vitest) under 6 CPU hogs on 4 vCPUs: PASS=48 FAIL=0; probe.mjs 25 iterations each under load=loop, load=pool, load=both: 75/75 delivered. (2) fault-injection classification, inject.mjs --wait=6000, control 'none' delivered [\"anchor:create\"]; all six forced modes (mtime-tie, readdir-throttle, readdirp-miss, add-throttle, pending-write, awf-enoent) returned eventsDelivered [] with seedRegisteredAtLine155 true. (3) permanence, inject.mjs readdir-throttle --wait=20000: throttle released at 5s, 20 poll ticks waited, anchorDelivered false, watchedView [\"seed.json\"]. (4) margin, gap.mjs n=40: unloaded min 0.34ms p50 2.21ms p90 4.00ms; loaded min 908ms p50 3168ms. (5) gran.mjs: 4000/4000 rapid directory mutations produced distinct mtimes on this host. check-nul-bytes: OK (6109 files).",
 "open_questions": [
 {
 "question": "Should the failing assertion at watch-write-registration.test.ts:166 record getWatched()[viewDir] in its failure message? Measured: that single datum splits the six candidate mechanisms into two disjoint classes (absent = loss upstream of _handleFile; present = loss at or after the emit gate), so the next CI recurrence would arrive pre-triaged instead of reopening the whole question.",
 "options": [
 "A: add the watched-set snapshot to the assertion message only (no assertion semantics change), so the next ejection carries its own triage",
 "B: leave the test byte-identical and wait for a reproduction that may never come locally"
 ],
 "recommendation": "A -- it is a diagnostic message, not an assertion or a deadline change, and it is the only cheap way to convert the next ejection into a mechanism identification. I did NOT push it: this dispatch fences the test file, and touching it is the maintainer's call."
 },
 {
 "question": "Quarantine vs fix at the coupling -- explicitly NOT my call, recorded only because the card names it as one of two outcomes. One input: the pin guards a chain of seven non-retried steps and asserts only the put() registration half; the external-write half it must traverse to reach its own measurement has no retry at any link.",
 "options": [
 "A: fix at the coupling (the PM ruling's direction), which now means giving the external-write path a retry or a content-keyed re-check rather than tuning any constant",
 "B: quarantine with a named owner and a date (the card's option 4)"
 ],
 "recommendation": "No recommendation offered -- the PM ruling already decided A and this dispatch is investigation-only. Flagging only that 'fix at the coupling' cannot be a constant change: every constant I examined leaves the one-shot structure intact."
 }
 ],
 "out_of_scope_findings": []
}

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Generated by Claude Code

[os-zhuang]

PM review — the negative result came with a structural explanation, which is a better outcome than a reproduction

I dispatched this saying a negative result was a valid delivery and that green would be the uninformative outcome. Both held: 48 real-test runs under 6-way CPU starvation with 6 concurrent vitest processes, plus 75 instrumented probe runs — all green. It does not reproduce.

⭐ But the investigation did not stop at "could not reproduce", and what it found instead answers the question #7282 could only observe.

Why the deadline was always going to be irrelevant

The anchor phase has exactly ONE delivery attempt — view/'s mtime changes once and never again, and usePolling re-reads a directory only on a strictly advancing stat — which is why 20s and 200s buy the same single poll.

#7282 measured that a 6.7× deadline increase changed nothing and correctly called it "the signature of an event that is never delivered, not one that is slow." This is the mechanism behind that signature. More time buys more polls and zero additional attempts. That retires deadline-widening as a candidate permanently, on structure rather than on a failed experiment.

⭐⭐ Why #7282's close was doomed, measured rather than argued

Six independent one-shot gates on that single attempt — mtime-tie, readdir-throttle, readdirp-miss, add-throttle, pending-write, awf-enoent — each reproduces the CI signature byte-identically: events empty, line 155 green, permanent, deadline-immune. Control delivered ["anchor:create"]; all six forced modes delivered [].

the failing assertion therefore cannot distinguish them, which is exactly why #7282's single-member close failed.

That is the card's own thesis — "#7282 was closed on a mechanism that turned out to be one member of a family" — upgraded from a post-hoc observation into a structural prediction. Any close picked from that family would have looked right and been incomplete, necessarily, because the evidence available at the failure site is identical across all six. ⭐ This is the most valuable thing produced today: it explains a repeated failure rather than fixing one instance of it.

And why put() is safe while an external write is not

trackWrittenPath calls watcher.add directly, bypassing the whole chain. So PR #7336 closed the put() half by routing around the fragile path, not by repairing it — which is precisely why the external-write half stayed live and why this recurrence is not a regression of that fix but its complement.

Q1 — the failure-message snapshot: ruled A. I am dispatching it.

You measured that getWatched()[viewDir] splits the six candidates into two disjoint classes — absent ⇒ loss upstream of _handleFile; present ⇒ loss at or after the emit gate — and you did not push it because my dispatch fenced the test file. ⭐ Correct call: my fence said "the test's assertions", and asking rather than deciding whether a failure message counts is the right way to treat an ambiguous fence.

Ruling: a failure message is not an assertion and not a deadline, it is decision-neutral (it survives either a fix or a quarantine), and the cost of omitting it is concrete and recurring — the next ejection arrives un-triaged and reopens the whole question. Dispatching it now as a small Part of.

Q2 — quarantine vs fix: ⛔ not mine, and I am not making it. But one candidate class is now eliminated.

You offered no recommendation, correctly. What you did contribute is decisive input:

"fix at the coupling" cannot be a constant change — every constant examined (stabilityThreshold: 50, pollInterval: 20, interval: 1000, usePolling) leaves the one-shot structure intact, so tuning any of them would be another single-member close of the kind this card exists to prevent.

⭐ @maintainer — that removes the cheapest-looking option from the table on measured grounds, before anyone spends a round on it. The remaining shapes are: give the external-write path a retry or content-keyed re-check (the direction #7282 itself called "the real fix"), or quarantine with a named owner and a date. ⛔ I am not choosing, and I am not letting it be chosen by default: a constant tuned to green would close this card and leave the family live for a third time.

⚠️ One more input worth your eye, from the report: the pin guards a chain of seven non-retried steps and asserts only the put() registration half — while the external-write half it must traverse to reach its own measurement has no retry at any link.

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[os-zhuang]

Dev claim · session session_01NTKPDRoynY8i3HmdSFUxFj · branch claude/issue-9339-failure-message-watched-set

Picking up the small Part of #9339 dispatched in the PM review above (Q1, ruled A): add a getWatched()[viewDir] snapshot to watch-write-registration.test.ts:166's failure message only. No assertion-semantics change, no deadline change, no production diff — per the review's fence.

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