One terminal iteration covering the whole spec. Four tasks, all on
`bench/baseline.json`:
- Task 1: pre-recapture JSON edit — drop `max_us` + `p99_9_us` × 3
latency arms (6 entries) and rewrite the `note` field forward-
looking. The 6 entries must go before `--update-baseline` runs
because `write_new_baseline` faithfully re-baselines anything
left in the file (recon Open Q). The note rewrite is folded in
here because `--update-baseline` preserves the existing note as-
is, so any change has to happen before recapture (or as a
separate post-recapture edit; one-edit is cleaner).
- Task 2: `bench/check.py --update-baseline` regenerates every
remaining `baseline` value from a fresh `bench/run.sh -n 5`,
updating `captured` → 2026-05-20 and `captured_via`.
- Task 3: acceptance §1 — fresh-HEAD replay → exit 0, 0 regressed,
57 metrics in summary (= pre-edit 63 minus the 6 drops).
- Task 4: acceptance §2 — synthetic injection (halve
`bench_list_sum.bump_s.baseline` via `jq`) → exit 1 + REGRESSION
row on that metric, then restore via `jq` and confirm a final
exit-0 replay.
Recon adjudications:
- Replay-source (recon Open Q1): fresh `bench/run.sh -n 5` for
replay, not the same output that produced the recapture.
Realistic acceptance scenario; with 10% throughput tolerance vs.
~1-2% measured run-to-run variance on the affected metrics
(run-1 / run-2 reproduction data in spec body), there is ample
margin.
- Note rewrite (recon Open Q2): forward-looking — drop stale
refs (JOURNAL workflow retired 8e586f4; the `*.max_us`
tolerance convention is now moot since the metric is gone),
replace with pointer to docs/specs/2026-05-20-bench-harness-
recalibration.md + closed issues #15 / #16. Spec lives where
the rationale lives; the note carries the gate-policy
one-liner only.
No Rust crate touched. `bench/check.py` / `bench/run.sh` /
`bench/latency_harness.py` unmodified.
Plan self-review (all 8 checklist items): clean. Step granularity
checked; Task 3 collapsed from two `bench/check.py` runs to one
(single 3-minute run captures both summary and exit code).
Ready for handoff to `skills/implement`.
Brummel
ddb50c3cb3