fix(skills): reap leaked cross-review refs/cr/* and temp diffs - #2195
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📝 WalkthroughWalkthroughPhase 1 now reclaims stale temporary diff files and scoped Estimated code review effort: 1 (Trivial) | ~5 minutes Mergeability Score: 🔵 Low · up to The new cleanup can remove unrelated temporary files or manually maintained review refs when their names match the reaper's patterns. The impact is bounded to cleanup targets, so the PR is mergeable with explicit owner awareness or follow-up to tighten both validation rules. Suggested reviewers: 🚥 Pre-merge checks | ✅ 4✅ Passed checks (4 passed)
✨ Finishing Touches🧪 Generate unit tests (beta)
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Inline comments:
In @.agents/skills/aicr-cross-review/SKILL.md:
- Around line 106-112: The cross-session reaper must use the same stable
skill-owned temporary root as live session diff-file creation, rather than
deriving it from the current TMPDIR. Update the temporary path setup and cleanup
logic around the cross-review session files and refs so reaping checks the
actual shared root, preserving refs for live sessions regardless of differing
TMPDIR values.
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Inline comments:
In @.agents/skills/aicr-cross-review/SKILL.md:
- Around line 108-112: Make the liveness marker key unique per PR by combining
the PR identifier n with SID, such as n-SID, instead of using SID alone. Apply
this same key consistently in Phase 1 lookups, HEAD-mismatch cleanup, RUNMARK
creation, and final cleanup, preserving the existing marker lifecycle behavior.
- Around line 106-113: The cleanup logic around the run marker, pinned refs, and
DIFFPATH must not remove an active run during long Codex waits or verification.
Refresh the active run marker throughout each long wait, and update
temporary-file cleanup to skip the current active run’s DIFFPATH; alternatively
enforce a workflow timeout below the 180-minute janitor threshold.
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Inline comments:
In @.agents/skills/aicr-cross-review/SKILL.md:
- Line 114: Update the temporary-file cleanup find command to include a
regular-file filter before deletion, so the janitor only removes stale matching
files and never directories.
- Around line 108-112: Update the ref-cleanup loop around KEY and the existing
suffix check to parse the PR/base key into its numeric PR component and
six-character SID, rejecting any key whose PR component is not numeric before
checking RUNS or calling update-ref. Preserve deletion only for valid ref shapes
with a missing run marker.
- Around line 107-114: Resolve the threshold inconsistency in the Phase 1 reaper
by selecting one authoritative retention period, then apply it consistently to
both -mmin predicates, the related documentation, and validation cases; if the
intended period is 24 hours, update the stated 180-minute objective instead.
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Inline comments:
In @.agents/skills/aicr-cross-review/SKILL.md:
- Around line 183-189: Update the Batch A step 3 setup around RUNS, RUNMARK,
SID, and DIFFPATH so RUNMARK is created via mktemp under the common Git
directory, then derive SID from that unique RUNMARK path. Create DIFFPATH
independently, and ensure PRREF and BASEREF use the SID derived from RUNMARK to
prevent same-PR runs from sharing refs or markers.
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Inline comments:
In @.agents/skills/aicr-cross-review/SKILL.md:
- Line 117: Update the temporary-file cleanup command in the janitor flow to
validate each candidate basename before deletion, requiring the exact
cross-review-pr<n>.<SID> format with a numeric PR number; preserve the age and
regular-file checks while excluding names such as cross-review-private.ABC123
and cross-review-pr123.foo.ABC123.
- Around line 143-150: Update the cleanup-loop warning around the three case
guards to document that both pr<n>-<SID> and base<n>-<SID> names can collide
with automatic candidates and may be deleted when their marker is absent.
Reserve both shapes for manual refs, while preserving the existing guidance
about the load-bearing guards and find-based deletion.
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✅ Multi-persona cross-review — Approve with comments
Method: 3 independent persona reviewers (Correctness/Shell · Concurrency & Blast-radius · Docs-accuracy/Domain) → adversarial senior meta-reviewer re-derived each finding from the resolved code. Reviewed at 7aa900d8.
Tier legend: 🔴 Blocker · 🟠 Major · 🟡 Minor · 🔵 Nitpick
Overall assessment
Careful, well-argued fix. The load-bearing invariant — marker written before refs (Batch B), deleted after refs (Phase 5) — is correct, and the concurrency interleavings (session-A-reaper vs session-B-mid-review, simultaneous starts, double-delete race) were each walked and none reap a live run's refs during normal operation. The three case guards genuinely fail-closed (the refs/cr/private-ABC123 → ivate-ABC123 example checks out), the shell parameter-expansion is sound, and find's flags are portable across GNU/BSD. Confirmed independently that git update-ref -d on a missing ref returns rc=0, so the double-delete race is benign.
No blockers, no majors. One 🟡 Minor is worth addressing — flagged independently by all three personas: the 24h gate measures age since run start (the marker is stamped once and never refreshed), not "inactivity" as the prose states, so a review that runs/stalls past 24h can have its own refs + diff reaped mid-flight with no in-run detection. Preferred fix is a marker refresh at each phase boundary (which also shrinks the real hazard to true stalls); at minimum, correct the wording. The 🔵 nitpicks are optional polish.
CodeRabbit's two earlier Major findings (TMPDIR-stability, gate duration) are already resolved in this diff.
Confirmed non-issues (examined, sound)
- Double
update-ref -drace → benign (rc=0 on missing ref, verified). - Ordering invariant (marker-before-refs / refs-before-marker) → sound across Batch B, Phase 5, and the abort path.
- SID same-PR/different-TMPDIR collision → correctly out of scope:
PRREF/BASEREFcollide first, so the<n>-<SID>marker key can't be worse; the<n>-<SID>vs<SID>-only decision is right and necessary. - All
case-guard / prefix-strip / split /??????SID logic → sound (mktemp's alphanumeric charset means SID has no-). findflag portability and-type fexcludingcr-runs/→ correct on GNU + BSD/macOS.- Cross-TMPDIR orphan diff files → documented acceptable; refs/markers still reaped from the shared common git dir.
Summary
🔴 Blocker 0 | 🟠 Major 0 | 🟡 Minor 1 | 🔵 Nitpick 4 Approve with comments
Closes the ref/temp-diff leak safely. The only item worth touching before merge is the 🟡 "inactivity" mislabel.
| Review phase and again in Cross-review, with Verify on top. A gate near the | ||
| expected duration would let a later Phase 1 reap a *live* run's marker, then its | ||
| refs, and the temp-file janitor would take its `DIFFPATH` with them — the run would | ||
| destroy itself. A day of inactivity is unambiguously dead, and since this reaper |
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🟡 Minor — Gate measures age-since-start, not "inactivity"; a live run past 24h reaps its own refs + diff
The marker is stamped once at Batch B start (: > "$RUNMARK", L194) and never refreshed, and the gate find … -mmin +1440 -delete (L107/117) reads mtime — so it measures wall-clock age since the run started, not inactivity. The prose here ("A day of inactivity is unambiguously dead") mislabels the one interleaving that can still eat a live run: a review that runs or stalls (hung subagent, left open overnight, waiting on user input) past 24h has its marker swept by a later session's step-1 find, its refs reaped by step-2, and its DIFFPATH taken by the janitor — with no in-run detection (unlike the HEAD-moved guard), surfacing as a confusing mid-review failure recoverable only by restart. Functionally safe today (automated runs ~2-3h ≪ 24h), but the justification is wrong, and it quietly undercuts the very next line's "Do not tune it down" guard rail.
Blast radius: Single run loses both refs/cr/* and its diff file mid-flight; later phases that re-git diff or re-read DIFFPATH break. Recoverable only by restart; inputs are recomputable.
Fix: Preferred: refresh the marker at each phase boundary (: > "$RUNMARK" on entry to Phase 2/3/4) so it becomes a genuine inactivity gate and the wording becomes true. Minimum: reword to "a run whose marker is a day old — stamped once at start, never refreshed — is unambiguously dead" and state that a run exceeding 24h has its inputs reaped and must restart. Same sentence is in the PR body's Implementation Notes.
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Prose fixed in 81ad9b896, and you are right that the word was wrong: the marker is stamped once at Batch B and never refreshed, so the gate measures age since it was stamped, not inactivity. The doc now says that explicitly. The same sentence appeared in the PR body and has been corrected there too.
I am not adding a marker heartbeat, though, for two reasons found while tracing it:
- Nothing between Batch B and Phase 5 resolves
PRREForBASEREF. The lanes are handed raw SHAs and a file path (workflow.mjs:46, 169, 206, 429), so reaping the refs only makes the fetched objects unreachable, and unreachable loose objects are still protected bygc.pruneExpire. Phase 5 deleting an already-deleted ref exits 0, so cleanup does not fail either. - The branch that does have consequence,
DIFFPATH, is gated on each diff file's own mtime (SKILL.md:118) and never consults the marker. So refreshing the marker would not protect it — the two halves are separate mechanisms, and a heartbeat would only address the harmless one.
A heartbeat would also make correctness depend on an agent remembering to touch the file across agent-driven phases. The doc now states what is measured and notes the janitor is gated independently, which seemed the better trade.
| ```bash | ||
| RUNS="$(git -C "<repo-path>" rev-parse --path-format=absolute --git-common-dir)/cr-runs" | ||
| find "$RUNS" -maxdepth 1 -type f -mmin +1440 -delete 2>/dev/null || true | ||
| git -C "<repo-path>" for-each-ref --format='%(refname)' 'refs/cr/pr*' 'refs/cr/base*' | |
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🔵 Nitpick — Legacy markerless refs reaped on sight with no age grace — the 24h-gate claim isn't universal
The ref loop has no mtime fallback: it deletes any shape-matching ref whose marker is absent ([ -e "$RUNS/$KEY" ] || update-ref -d). 0.3.21 refs never wrote markers, so a 0.3.22 reaper deletes them immediately, regardless of age; the 24h gate (L168-175) only bounds marker-bearing refs.
Blast radius: One-time transition only; a 0.3.21 review in-flight across the upgrade loses its refs early. Harmless (nothing between Batch B and Phase 5 re-reads the refs; the diff file has its own 24h janitor gate). Documented in the PR body's Rollout notes.
Fix: Optional: add a clause to the 24h-gate paragraph noting markerless refs are reaped on sight, so it isn't read as covering every ref.
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No change here.
It is a one-time transition, and it is precisely the cleanup this PR exists to perform on the already-leaked refs. The Risk Assessment states it.
An mtime fallback would also reintroduce the failure the doc refutes at SKILL.md:123-129: packed refs have no per-ref mtime after git gc, so the fallback would silently stop reaping — which is the original bug in a quieter form.
| case "$KEY" in *-*) ;; *) continue;; esac # must have both components | ||
| case "${KEY%-*}" in ''|*[!0-9]*) continue;; esac # <n> is a PR number | ||
| case "${KEY##*-}" in ??????) ;; *) continue;; esac # <SID> is mktemp's six chars | ||
| [ -e "$RUNS/$KEY" ] || git -C "<repo-path>" update-ref -d "$REF" |
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🔵 Nitpick — Batch A step 3 relies on set -e being off but never asserts it; loop update-ref -d lacks || true
The two finds carry || true; the inner git update-ref -d "$REF" does not. Batch B declares set -euo pipefail (L183) but Batch A never states its set state, so step 3 implicitly relies on set -e being absent. If the harness ever ran it under set -e, a lost ref-delete race would abort reaping early (still harmless — best-effort — but silently incomplete).
Blast radius: Reaping is best-effort, so worst case is a stale ref surviving one extra run. No output corruption.
Fix: Add || true to the loop's update-ref -d, or a one-line note that step 3 runs without set -e.
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Leaving the shell as-is.
The loop is the right side of a pipeline, so it runs in a subshell. Even if set -e were enabled, a failed update-ref -d would abort step 3 only, and step 3 is best-effort with nothing downstream depending on it — the next run redoes the reaping. Adding || true would also mask a genuine ref-store failure, which is the one case worth noticing.
The undeclared set state is a fair observation; the block follows the same convention as the other non-set batches in the file.
| them, and they accumulate in the same slow way the worktrees above do. | ||
|
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||
| ```bash | ||
| RUNS="$(git -C "<repo-path>" rev-parse --path-format=absolute --git-common-dir)/cr-runs" |
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🔵 Nitpick — New hard floor on git ≥2.31 (--path-format=absolute)
Both the reaper and the Batch B marker path newly rely on git rev-parse --path-format=absolute (added git 2.31, 2021). --git-common-dir alone predates it.
Blast radius: Negligible in any modern environment; just a raised floor introduced by this PR.
Fix: None needed; noting for completeness.
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Noted, no change — matching your own assessment.
The flag landed in git 2.31 in 2021 and this is a developer-machine agent skill rather than a shipped runtime, so the raised floor is not a practical constraint. Worth having in the thread for the record.
| guarantees distinct names within one directory. It guarantees nothing across | ||
| directories, so same-PR runs under different `TMPDIR` roots can still collide — | ||
| but on `$SID` itself, which makes `PRREF` and `BASEREF` collide first. That is a | ||
| property of how Batch B derives `$SID`, not of this reaper, and is tracked |
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🔵 Nitpick — "tracked separately" implies a filed ticket; PR body says "left to a follow-up"
The SID-collision deferral says it "is tracked separately," while the PR body's Out-of-Scope says "left to a follow-up." If no issue is actually filed, the latter is accurate.
Blast radius: Cosmetic wording only.
Fix: Align the two phrasings.
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Fixed — SKILL.md now reads "left to a follow-up", matching the PR body.
Worth recording that this was more than a wording mismatch. There is no filed issue: searches of this repo for "SID collision", "cross-review SID", and "cross-review refs/cr" return nothing, while control searches return results normally. So the original phrasing asserted a tracking item that does not exist, and it was the justification for not fixing the collision here. The follow-up wording is the accurate one.
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A cross-review session killed between Phase 1 Batch B and Phase 5 leaks
its two session-scoped refs (refs/cr/pr<n>-<SID>, refs/cr/base<n>-<SID>)
and its temp diff file permanently. Phase 5 deletes them only on a clean
finish, and the skill correctly forbids deleting another session's refs,
so nothing reclaims a dead run's. Observed 14 refs/cr/* plus an orphaned
${TMPDIR}/cross-review-pr*.<SID> in one clone. Same slow-accumulation
class as the worktree leak that reached E2BIG at ~70 worktrees.
Batch B now drops a liveness marker at <common-git-dir>/cr-runs/<n>-<SID>
before creating the refs, and deletes it last in Phase 5. A new Batch A
step reaps markers older than 24 hours, then deletes any skill-shaped ref
whose marker is gone, and finally reclaims stale temp diff files.
Liveness is keyed on that marker because the two obvious alternatives are
both wrong:
- Not the ref. git gc packs refs/cr/* into packed-refs, after which the
per-ref file no longer exists and an mtime gate silently no-ops; git
fetch, which Batch B runs, triggers gc --auto. refs/cr/* also has no
reflog (core.logAllRefUpdates covers only refs/heads, refs/remotes,
refs/notes, and HEAD), and %(creatordate) is the commit's date.
- Not the temp diff file. TMPDIR is not stable across sessions or even
within one: under the Claude Code sandbox it is /tmp/claude-<uid>,
and with the sandbox bypassed it is the shell default. A reaper
keyed on the diff file would delete a live session's pinned refs
whenever the two disagree.
The marker sits under the common git dir, so every worktree of a clone
shares one view exactly as refs/cr/* do, git never packs or prunes it,
and it keeps a real creation timestamp.
The key is <n>-<SID>, not <SID>: mktemp guarantees the full filename is
unique, not the suffix, so concurrent reviews of different PRs can be
handed the same six characters. Their refs stay distinct, but a
<SID>-keyed marker would be one shared file and the first run to finish
would strip the other's protection.
The gate is 24 hours because nothing enforces an end-to-end limit on a
review: Codex gets a five-wait, ~45-minute budget in Review and again in
Cross-review, with Verify on top. A gate near the expected duration would
let a later Phase 1 reap a live run's marker and refs, and take its
DIFFPATH with them.
Deletion is bounded by three guards, all load-bearing: a candidate must
split into two components, carry a numeric <n>, and end in a six-character
<SID>. Prefix-stripping alone would not do, since refs/cr/pr* also matches
refs/cr/private-ABC123, which strips to ivate-ABC123 and passes a
suffix-only check. Hand-made bookmarks therefore survive unless named
literally pr<digits>-<six characters>. The temp-file janitor is -type f so
a directory matching the diff-file pattern is never removed, and deletion
uses find -delete rather than rm, consistent with the rest of the skill.
Signed-off-by: Yuan Chen <yuanchen97@gmail.com>
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✅ Re-review — Approve
Delta re-review of 81ad9b89 (my prior approval on 7aa900d8 was auto-dismissed by the new push). The PR's own change is still SKILL.md only — the other files in the compare are rebase drift from main, not part of this PR. The fix commit introduces no new logic, only the two prose corrections below, so there are no net-new findings.
Prior-feedback status
| # | Prior finding | Disposition |
|---|---|---|
| 1 | 🟡 Gate measures age-since-start, not "inactivity" | ✔️ Addressed — prose now reads "age since Batch B stamped the marker, not inactivity … written once and never refreshed." Heartbeat correctly declined: I verified workflow.mjs never resolves PRREF/BASEREF, so reaping a live run's refs is harmless, and DIFFPATH is gated independently on its own mtime — a marker heartbeat would protect only the harmless half. My original blast-radius was, if anything, overstated. |
| 2 | 🔵 Legacy markerless refs reaped with no age grace | ◐ Declined — sound — an mtime fallback would reintroduce the packed-refs-no-mtime bug the doc refutes at L123-129; the one-time transition is stated in Risk Assessment. Agreed. |
| 3 | 🔵 Batch A set -e unstated / loop update-ref -d lacks || true |
◐ Declined — sound — the loop is the RHS of a pipeline (subshell), the step is best-effort, and || true would mask a genuine ref-store failure. Agreed. |
| 4 | 🔵 New git ≥2.31 floor | ⊘ No change needed — dev-machine agent skill, matches my own assessment. |
| 5 | 🔵 "tracked separately" vs "follow-up" | ✔️ Addressed — now "left to a follow-up"; author confirmed no issue is actually filed, so it was more than cosmetic. |
Verdict
🔴 Blocker 0 | 🟠 Major 0 | 🟡 Minor 0 | 🔵 Nitpick 0 open Approve
The one substantive item (the "inactivity" wording) is fixed, and the three declined nitpicks each carry correct engineering rationale I agree with. Nothing outstanding — approving.
(Note: yuanchen8911's review-thread entries are the PR author's own replies, not an independent human review.)
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Summary
Adds a bounded reaper to the
aicr-cross-reviewskill's Phase 1 so a review session killed mid-run no longer leaks its tworefs/cr/*and its temp diff file permanently.Motivation / Context
Phase 1 Batch B pins each review's inputs by fetching two session-scoped refs,
refs/cr/pr<n>-<SID>andrefs/cr/base<n>-<SID>, where<SID>is themktempsuffix shared with the temp diff file. Phase 5 deletes both on a clean finish, and the skill correctly forbids deleting another session's refs — a live review must not have its pinned inputs yanked.Nothing reclaims a dead run's. One clone had accumulated 14
refs/cr/*plus an orphaned${TMPDIR}/cross-review-pr*.<SID>, the oldest from runs long finished. This is the same slow-accumulation class as the worktree leak that reachedE2BIGat ~70 worktrees and needed a fresh session to recover. The CodeRabbit lane already reaps itscr-rabbit.*worktrees at 120 minutes; the ref side had no equivalent.Fixes: N/A
Related: #2172
Type of Change
Component(s) Affected
cmd/aicr,pkg/cli)cmd/aicrd,pkg/server)pkg/recipe)pkg/bundler,pkg/component/*)pkg/collector,pkg/snapshotter)pkg/validator)pkg/errors,pkg/k8s)docs/,examples/).agents/skills/aicr-cross-review/SKILL.mdImplementation Notes
Batch B drops a liveness marker at
<common-git-dir>/cr-runs/<n>-<SID>before creating the refs, and Phase 5 deletes it last. A new Batch A step reaps markers older than 24 hours, deletes any skill-shaped ref whose marker is gone, then reclaims stale temp diff files.Liveness is keyed on that marker, and both obvious alternatives are wrong. This is the only non-trivial decision here.
git gcpacksrefs/cr/*intopacked-refs, after which the per-ref file under.git/refs/cr/no longer exists and an mtime gate silently stops reaping.git fetch— which Batch B itself runs — triggersgc --auto, so this is reachable in normal use, and a reaper that degrades silently is the worst shape for this class of fix. The substitutes fail too:refs/cr/*has no reflog, sincecore.logAllRefUpdatescovers onlyrefs/heads,refs/remotes,refs/notes, andHEAD; and%(creatordate)is the commit's date, so a ref created a minute ago on yesterday'smainreports "21 hours ago".TMPDIRis not stable across sessions, or even within one. Under the Claude Code sandbox it is/tmp/claude-<uid>; with the sandbox bypassed it is the shell default (/var/folders/…/T/on macOS). A reaper keyed on the diff file would fail to see a live session's file whenever the two disagree and would delete that session's pinned refs — precisely what the skill must never do.The marker sits under the common git dir, so every worktree of a clone shares one view exactly as
refs/cr/*do. Git ignores unknown entries there, so nothing packs or prunes it and it keeps a real creation timestamp. The temp-filefindis now only a janitor: it reclaims diff files in whateverTMPDIRthis session sees, and reclaiming none is harmless.The key is
<n>-<SID>, not<SID>.mktempguarantees the full filename it returns is unique; it does not reserve the suffix. Two concurrent reviews of different PRs pass different templates, so both can receive the same six characters. Their refs stay distinct, but a<SID>-keyed marker would be a single shared file, and whichever run finished first would strip the other's protection. Reviews of the same PR are safe whenever they share aTMPDIR, sincemktempguarantees distinct names within one directory. It guarantees nothing across directories, so same-PR runs under differentTMPDIRroots can still collide — but on$SIDitself, which makesPRREFandBASEREFcollide before the marker does. That is a property of how Batch B derives$SIDonmaintoday, untouched by this PR, and is left to a follow-up rather than folded in here.The gate is 24 hours, deliberately far above any real run. Nothing enforces an end-to-end limit on a review: Codex gets a five-wait, ~45-minute budget in the Review phase and again in Cross-review, with Verify on top. A gate near the expected duration would let a later Phase 1 reap a live run's marker and then its refs, with the temp-file janitor taking its
DIFFPATHtoo — the run would destroy itself. The gate measures age since Batch B stamped the marker, not inactivity — the marker is written once and never refreshed — so a run still alive a day later is outside every documented budget and is treated as dead. The temp-file janitor is gated independently, on each diff file's own mtime, so refreshing the marker would not coverDIFFPATHeither way. Since this reaper exists for leaks that accumulate over days, waiting a day to collect one costs nothing.Bounds. Deletion is gated by three checks, all load-bearing: a candidate must split into two components, carry a numeric
<n>, and end in a six-character<SID>. Prefix-stripping alone would not do —refs/cr/pr*also matchesrefs/cr/private-ABC123, which strips toivate-ABC123and would pass a suffix-only check. Hand-made bookmarks such asrefs/cr/2183-r5andrefs/cr/2187-test— deliberate, and often pinning active work — therefore survive unless named literallypr<digits>-<six characters>. The temp-file janitor is-type f, so a directory matching the diff-file pattern is never removed, and deletion usesfind … -deleterather thanrm, consistent with the rest of the skill: managed permission policies gaterm:*behind a confirmation prompt, and a background lane blocked on a prompt stalls the review.No
workflow.mjschange is needed — the refs are created and deleted entirely on the SKILL.md side.Testing
Doc-only change to a skill file. Nothing in
Makefile,tools/, or.github/workflows/lintsSKILL.md, and there are no Go, YAML, ordocs/changes, somake qualifycannot regress from this and was not run.The reaper was verified empirically in a scratch repository under every hostile condition at once:
git gc --prune=nowfirst, so all refs are packed and no per-ref mtime exists;TMPDIRexported to a path unrelated to the producer's, reproducing the cross-session mismatch; two different PRs handed the samemktempsuffix, one finished and one live; a dead run aged past the gate; a live run four hours in; hand-made bookmarks that survive prefix-stripping (private-ABC123,base-line-DEPLOY,prod-v1beta,pr123456) alongside ordinary ones; and a directory matching the janitor's diff-file pattern.Every live and deliberate ref survived; only the dead runs' refs and markers were reaped. Two results carry the weight:
pr2195-ABC123survived whilepr2183-ABC123was reaped, though the two shared a suffix that a<SID>-keyed marker would have conflated; andprivate-ABC123survived, which a suffix-only check would have deleted.The two ref-timestamp traps were confirmed separately:
git reflog show refs/cr/...returns nothing, and%(creatordate)reports the commit's date.git rev-parse --path-format=absolute --git-common-dirwas confirmed to resolve to the same path from a linked worktree and from the main checkout, matching howrefs/cr/*are shared. The ~45-minute-per-phase Codex wait budget behind the 24-hour gate is documented atworkflow.mjs:261.Out of Scope
$SIDis derived fromDIFFPATH, andmktempguarantees uniqueness only within a single directory. Two same-PR runs under differentTMPDIRroots can therefore be handed the same suffix, which collidesPRREFandBASEREF— one run's fetch force-updates the other's pinned refs. That is pre-existing onmain:DIFFPATH=$(mktemp …),SID=${DIFFPATH##*.}, and both ref assignments are unchanged by this PR, which touches only theecholine beneath them. Fixing it means restructuring Batch B's identity scheme, a strictly larger change than the leak this PR addresses, so it is left to a follow-up.Known limitation, accepted. The temp-file janitor's
cross-review-pr*.??????glob would also match contrived names such ascross-review-private.ABC123.mktempcannot produce those, and this skill is the only writer ofcross-review-pr*intoTMPDIR, so the glob's realistic population is exactly the diff files it collects. Validating<n>numerically would mean converting a singlefind … -deleteinto a loop, which is not worth it against a failure mode of a stale scratch file surviving a day longer.Risk Assessment
Rollout notes: Affects only agent-facing skill instructions; no product code, no user-facing behavior.
One transition caveat, stated for completeness: refs created under the older instructions carry no marker, so the first run of the new ones reclaims them. For the leaked refs this PR is about that is exactly the intended cleanup. But a review still in flight under the old instructions at that moment would also lose its pinned refs and have to be restarted. The window is one-time and narrow — it closes as soon as every clone has the new instructions — and the cost is a restarted review, not lost work.
Checklist
make testwith-race) — N/A, no Go changesmake lint) — N/A, no linted file types changedgit commit -S)