The reusable artifact here was never the vendored targets — it is the
discipline: prove equivalence, prove significance, or claim nothing. This
packages it as a Claude Code skill usable from any repo.
Two modes. `verify` works anywhere, on any two shell commands in any
language: equivalence before timing -> A/A calibration -> interleaved A/B
with a bootstrap CI -> a verdict decided by the CI lower bound, never the
median. `attempt` drives the full in-repo loop (gates, pristine-baseline
verdict, ledger row, ROI report).
It drives the real bench-runner binary and refuses rather than degrade: on
an unsupported host, or with no trust layer reachable, preflight stops and
says so instead of falling back to a hand-rolled timing loop. A second copy
of the statistics is a second thing that can lie. A refusal ends the claim,
not the work.
An adversarial review of the skill caught six high-severity defects, all
fixed here — several of them the very errors the skill exists to prevent:
- verify mode had no risk classification at all. bench-runner emits only
accepted/rejected-bench; needs-human-review is minted by the in-repo
verdict path, which verify does not run. A concurrency change with
byte-identical output would have sailed through as "accepted". The skill
now makes the agent the classifier and says so explicitly.
- the accept template exposed `pin_prefix`, which is inert for
compare/aa/calibrate (only `verdict` reads it) — an agent would have set
it and reported pinning that never happened. Now documents wrapping both
sides in taskset instead.
- the equivalence gate compared stdout only, so two commands that write to
stderr and a dist/ tree would "GOLDEN PASS" on two empty files. Now hashes
stdout + stderr + exit code + artifact tree, and an empty diff over empty
output is a failed gate, not a passed one.
- nothing told the agent to build two coexisting immutable artifacts, so a
`cargo run` baseline could rebuild from the patched tree mid-bench — the
exact trap phase1-verdict-smoke-001 recorded.
- service mode was documented as generic HTTP. It is not: the server must
take <port> <doc> <iters>, print READY, and close the connection. A stock
Express app hangs the harness forever. Contract now stated.
- the CI refusal test could not pass: preflight also walks up from its own
location, so running it in-place found this very repo. The test now copies
the skill out of the tree first.
CI job `skill-preflight` asserts the contract that matters — resolve when a
trust layer is reachable, REFUSE when it is not, and work when consumed from
another repo via PELTIER_HOME. It deliberately does not assert a statistical
outcome: a shared runner is too noisy for that, which is precisely why the
skill calibrates before it claims.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
An adversarial audit found the enforcement story ahead of the code: gates
that were documented as hard gates were advisory, manual, or absent, and
several human-facing claims outran the machine record. This makes the
claims true.
High findings
- Differential fuzz was documentation, not enforcement: verdict hardcoded
fuzz_iters=0 and diff-test hardcoded the gate to Skipped, while the case
studies claimed 10k-iteration fuzz on the same wins. Fuzz is now a real
pipeline gate (strict FUZZ-RESULT contract, executed count recorded), and
it is inherently baseline-vs-candidate, so it runs on the accept path and
reports Skipped in the standalone `just gates` flow. New hard rule: a
machine `accepted` verdict is impossible unless the fuzz gate actually
passed — otherwise it caps at needs-human-review.
- The agent's system prompt claimed FP/concurrency/unsafe patches were
"routed to human review automatically". No such mechanism existed. Added
a conservative lexical risk classifier (crates/verdict/src/risk.rs) that
forces needs-human-review on any would-be accept carrying those signals;
fp-tolerance equivalence always signals.
- The local verdict path ran agent-influenced code unsandboxed. It now runs
under scripts/no-net.sh (network namespace) and fails closed. Upstream
test suites are hash-verified against corpora/<t>/TESTSUITE.sha256 when
present (scripts/pin-testsuite.sh generates them).
Also fixed, found while fixing the above
- The pipeline script's `set -e` was inert (brace group as the left operand
of `&&`), so a failing candidate build did not abort the run and verdict
could bench a stale binary. Now a scoped subshell whose status is branched
on at top level.
- A wrapper that exits before exec'ing (no-net.sh refusing, bad wrapper path)
stranded RUNNING.lock and left read_verdict polling forever. Failure
accounting now lives outside the wrapper.
- harnessd's patch allowlist ignored git rename/copy headers and --no-prefix
diffs; the rename-escape case is now a committed regression test.
- The workspace did not compile on Windows (ungated Unix APIs). cfg-gated;
71 portable tests now run on both platforms.
- pin-check regenerated the corpus manifest instead of verifying it; it is
now verify-only, with a deliberate `just pin-corpus` to re-pin.
- Max RSS is captured per run on Unix; PMU counters are opt-in diagnostics
(compare --perf-stat), never part of the accept decision.
Docs now match the code, including what is NOT yet enforced: no target ships
a TESTSUITE.sha256 pin, no target declares [build].tsan, and matmul is not
wired to the fp-tolerance gate — each is stated as mechanized-but-inert
rather than done. Corrected the stale "33 ledger rows" (34), the playbook's
class-3 cJSON win (rejected), adversarial-review.md's sanitizer-separation
claim (five accepted rows carry sanitizers_clean=false), the unsupported
"40,000 requests" figure, and the blanket "historical rows record
fuzz_iters=0" (8 of 10; phase0-tokei-002/-003 record 4,332).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
benbrownandGitHub
