Answer

The solution is written to /workspace/solution.md. Here it is:

---

gitreins-guard-hook-timeout-under-concurrent-load

Verdict: not a code bug. The Hermes‑DAGger pre‑commit hook is supposed to fail closed. Under sibling-fleet load it exhausted its wall-clock budget, emitted the fail-open PASS fingerprint, and the DAGGER‑0960 wrapper correctly refused that fingerprint and blocked the commit. Recovery is retry after load drops, with an independent lane re-verification first — never --no-verify.

1. Symptom

Committing from a Hermes‑DAGger worker fails with exit code 1:

pre-commit: running gitreins guard ...
gitreins guard: hook_timeout=300s test_mode=full
gitreins guard: go test -race -timeout 25m ./...
gitreins guard: <fail-open PASS fingerprint>          # killed at 300s
DAGGER-0960: REJECT fail-open PASS fingerprint (no fail-closed completion)  exit 1

Observed twice consecutively at load 26–30; commit landed green on retry after load fell.

2. Root-cause analysis

No defect in gitreins, the hook, or the wrapper. Pure contention + deliberate policy:

1. Budget mismatch — hook_timeout=300s supervises go test -race -timeout 25m ./... (1500s). Even idle this is tight; under load it always times out.
2. Contention — sibling fleet workers run concurrent race-enabled full-module test batteries; load 26–30 oversubscribes CPU.
3. External kill — at 300s the supervisor terminates gitreins guard before it can reach its own -timeout 25m.
4. Fail-open artifact — an unfinished supervised run emits the fail-open PASS sentinel.
5. Fail-closed enforcement — DAGGER‑0960 treats a fail-open PASS without a fail-closed completion as untrusted and rejects. Working as designed.

The go_lint isolated-file typecheck false-FAIL is a separate reporting quirk, not the cause. Not the fix: editing the fingerprint check, disabling DAGGER‑0960, or --no-verify.

3. Exact fix

3.1 Immediate recovery

# 0) Confirm the host is no longer contended.
uptime                      # want load ~< nproc, not 26-30
nproc
pgrep -af 'go test' || echo "no sibling go test batteries running"

# 1) Full-module lint (NOT an isolated file — avoids the false-FAIL artifact).
golangci-lint run ./...

# 2) Targeted package tests for the staged .go files.
PKGS=$(git diff --cached --name-only -- '*.go' \
  | xargs -r -n1 dirname | sort -u | sed 's#^#./#' | sed 's#^\./\.$#./#')
echo "Testing: $PKGS"
go test -race -count=1 $PKGS

# 3) Retry the commit through the hook.
git commit

3.2 Durable mitigation

Option A — align the hook budget with the lane budget:

# .pre-commit-config.yaml
- id: gitreins-guard
  name: gitreins guard (Hermes-DAGger)
  entry: gitreins guard
  language: system
  pass_filenames: false
  timeout: 1800     # was 300; must exceed go test -timeout (1500s)

# .gitreins.toml
[guard]
hook_timeout = 1800   # seconds; must exceed go test -timeout (1500s)
test_mode    = "full"

Option B — serialize fleet test batteries:

flock -w 2400 /var/lock/hermes-go-test.lock \
  go test -race -timeout 25m ./...

Or gate on load before starting the full lane:

for i in $(seq 1 60); do
  load=$(cut -d' ' -f1 /proc/loadavg)
  awk -v l="$load" -v n="$(nproc)" 'BEGIN{exit !(l < n)}' && break
  sleep 30
done

Do not weaken test_mode as the only gate; if the full lane moves to CI, make it required and branch-protected.

4. Verification

# 4.1 Contention, not a real failure: the lane passes on a quiet host.
go test -race -timeout 25m ./... ; echo "exit=$?"   # expect 0

# 4.2 Lint artifact: whole-module is authoritative; isolated-file may false-FAIL.
golangci-lint run ./... ; echo "module exit=$?"
FILE=$(git diff --cached --name-only -- '*.go' | head -1)
[ -n "$FILE" ] && golangci-lint run "$FILE"

# 4.3 Fix works: under deliberate load the guard concludes fail-closed,
#     never a bare fail-open PASS.
grep -nE 'timeout|hook_timeout' .pre-commit-config.yaml .gitreins.toml
yes > /dev/null &
git commit --allow-empty -m "guard budget smoke test"

Checklist: load low; golangci-lint run ./... green; targeted tests green; commit retried via git commit (not --no-verify); hook_timeout > go test -timeout or batteries serialized; wrapper reported fail-closed completion.

5. Takeaway

A 300s hook budget supervising a 25m lane under load 26–30 must time out, and DAGGER‑0960 is right to reject the resulting fail-open PASS. Fix the budget/contention, verify lanes independently, retry — never bypass the hook.

# Evidence
- Problem class: gitreins-guard-hook-timeout-under-concurrent-load
- Model: openrouter/deepseek/deepseek-v4.1-flash
- Solved: 2026-10-04T07:21:36.101Z
- Verification: solution produced by pi in sandbox; see signatures.json

{"description": "", "environment": "", "language": "", "model": "openrouter/deepseek/deepseek-v4.1-flash", "problem_class": "gitreins-guard-hook-timeout-under-concurrent-load", "provider": "openrouter", "solved_at": "2026-10-04T07:21:36.105Z", "version": ""}