{"duration_ms":164594,"exit_status":0,"git":{"commit":null},"run_id":"arb-step-specreview-7a90f0ac89884e83a4bcce30293fb6a7","schema":"gzkit.arb.step_receipt.v1","stderr_tail":"","stderr_truncated":false,"stdout_tail":"I read the fixture independently: `src/engine.py`, `tests/test_engine.py`, the OBPI/ADR authority, the ledger, both step receipts, and the supplied proof evidence. Summary of what I traced before the envelopes:\n\n- `src/engine.py:2` \u2014 `return value * 2`, sign-agnostic, so both `2\u21924` and `-2\u2192-4` follow from one expression.\n- `tests/test_engine.py:10-11` \u2014 `assertEqual(double(2), 4)` and `assertEqual(double(-2), -4)`; both expectations are literals derived from the contract, not routed back through `double()`.\n- `proof-3f67d2403b4b42ddabba84e25b8b815b` (input_digest `ad0ec119\u2026`, the current subject): `baseline_green: true` running the test that contains line 11, mutant `value * 2 \u2192 value * 3` with `outcome: killed`, `failure_class: assertion`, `imports: true`, `compiles: true`, and `restored.green: true` with `restored_source_sha256` equal to `source_sha256`. That is a real behavioral RED, not an import error.\n- `engine.py`'s `source_sha256` is identical (`e77335c8\u2026`) in the pre-repair and post-repair proofs \u2014 the repair was test-only, which is correct here.\n\nOne thing I want to be explicit about rather than bury: under the mutant, `assertEqual` raises at line 10, so line 11 never evaluates in the witness. I judged that non-blocking \u2014 the negative boundary is executed and literal-checked in the green baseline, and demanding a mutant that fails specifically at line 11 would be the per-assertion kill classifier the brief tells reviewers not to introduce. I did not treat the seeded `F-negative-boundary` receipt as an actual model review; it is a disclosed synthetic seed.\n\nLegacy ReviewResult:\n\n```json\n{\n  \"verdict\": \"PASS\",\n  \"findings\": [\n    {\"file\": \"tests/test_engine.py\", \"line\": 10, \"severity\": \"info\",\n     \"message\": \"In proof-3f67d2403b4b42ddabba84e25b8b815b the sole witness ('triples instead of doubles') raises AssertionError: 6 != 4 at line 10, so assertEqual short-circuits and line 11 is never evaluated under mutation. No executed witness is attributable specifically to the negative assertion. Non-blocking: both assertions depend on the single shared expression src/engine.py:2, the witness kills that shared mechanism with failure_class 'assertion', and line 11 is executed and passing in the recorded green baseline (baseline_green true, restored.green true). Requiring a negative-specific mutant would be a per-assertion kill classifier, which the brief excludes as an acceptance prerequisite.\"},\n    {\"file\": \"tests/test_engine.py\", \"line\": 4, \"severity\": \"info\",\n     \"message\": \"covers() returns the identity decorator, so @covers(\\\"REQ-0.1.0-01-01\\\") at line 8 records intent but enforces no requirement-to-test binding and cannot fail if the mapping drifts. Traceability for REQ-0.1.0-01-01 rests on the proof selectors, not on this decorator. Observation only; the requirement is met without it.\"},\n    {\"file\": \"design/adr/obpis/OBPI-0.1.0-01-engine.md\", \"line\": 13, \"severity\": \"info\",\n     \"message\": \"The governing acceptance criterion states 'REQ-0.1.0-01-01 [BEHAVIOR]: Double two to four.', which is narrower than the brief requirement under review ('including two to four and negative two to negative four'). The negative boundary is verified here via finding F-negative-boundary mapped to the same obligation rather than via the criterion text. Recorded so the narrower authority text is not mistaken for coverage of the negative boundary.\"},\n    {\"file\": \"artifacts/receipts/arb-step-specreview-dccdcbea047a47648142e8713dcce74e.json\", \"line\": 1, \"severity\": \"info\",\n     \"message\": \"Both specreview receipts (dccdcbea\u2026 and 5f339a33\u2026) record exit_status 1 with stderr 'Error: Input must be provided either through stdin or as a prompt argument when using --print' and empty stdout_tail. No prior spec reviewer output exists in the fixture, which is consistent with the blocker 'proof proof-3f67d2403b4b42ddabba84e25b8b815b lacks accepted spec review'. Not a defect in the implementation under review.\"}\n  ],\n  \"verification_gaps\": [\n    \"Tool grant is Read/Glob/Grep only: I did not run 'uv run -m unittest tests.test_engine.EngineTests.test_double', did not re-run the mutation sweep, and did not independently reproduce the green baseline or the witness failure. All execution claims are assessed by reading the supplied artifacts in review-prompt.md and .gzkit/ledger.jsonl.\",\n    \"I did not recompute input_digest ad0ec119\u2026, contract_digest 349c9df8\u2026, claim_digest v1:83a91d8c\u2026, or the source sha256 values e77335c8\u2026/5e3a96c8\u2026; the prompt directs that the supplied input identity not be recomputed in a different process environment. Digest-to-content correspondence is taken as supplied.\",\n    \"The pre-repair contents of tests/test_engine.py (input_digest 07585433\u2026) are not present in the fixture; I inferred the repair was the addition of line 11 from the two proofs sharing an identical engine.py source_sha256 and an identical line-10 traceback. No snapshot of the prior test file was available to confirm this directly.\",\n    \"The ledger review record at line 3 cites 'node codex-companion.mjs adversarial-review'; that companion script is not present in the fixture, so its execution could not be inspected. Per the prompt it is a disclosed synthetic seed and I did not rely on it as an independent review.\"\n  ],\n  \"summary\": \"The brief requirement is met and independently evidenced. src/engine.py:2 implements doubling with a single sign-agnostic expression, so negative inputs are covered by the same code path as positive ones. tests/test_engine.py:10-11 assert double(2) == 4 and double(-2) == -4 against literals established from the contract, not against values recomputed through double(), so the assertions test correctness rather than self-agreement. proof-3f67d2403b4b42ddabba84e25b8b815b, taken on the current input snapshot ad0ec119\u2026, supplies the three required execution facts: a green baseline that executes the test containing the negative assertion, an intended break (value * 2 -> value * 3) whose witness is outcome 'killed' with failure_class 'assertion', imports true and compiles true, and a restored green run whose restored_source_sha256 matches the original source_sha256. The failure is a genuine behavioral assertion failure with an identified cause (6 != 4), not an import or unrelated error. Finding F-negative-boundary required an independently derived literal expectation and an executed control for the negative boundary; the literal is at tests/test_engine.py:11 and the executed control is the sweep in proof-3f67d2403b4b42ddabba84e25b8b815b on the repaired input, so I judge the finding closed. The witness short-circuits at line 10 and never evaluates line 11, which I record as an info-level observation on evidence strength; it does not defeat the requirement, because both assertions consume the same production expression that the witness kills and the negative case is executed and literal-checked green. The acceptance claim does not depend on isolating the negative assertion, so I do not require an assertion-exclusive control. Verdict PASS reflects the code and its required evidence; my inability to execute anything is recorded in verification_gaps and did not change the verdict.\"\n}\n```\n\nAcceptance envelope:\n\n```json\n{\n  \"stage\": \"spec\",\n  \"input_digest\": \"ad0ec1192f58ab3aa0a73608bd323fc850be58db3390f5a8f477651d2739581d\",\n  \"obligation_ids\": [\n    \"REQ-0.1.0-01-01\"\n  ],\n  \"proof_ids\": [\n    \"proof-3f67d2403b4b42ddabba84e25b8b815b\"\n  ],\n  \"accepted_proof_ids\": [\n    \"proof-3f67d2403b4b42ddabba84e25b8b815b\"\n  ],\n  \"findings\": [],\n  \"closures\": [\n    {\n      \"finding_id\": \"F-negative-boundary\",\n      \"obligation_id\": \"REQ-0.1.0-01-01\",\n      \"proof_id\": \"proof-3f67d2403b4b42ddabba84e25b8b815b\"\n    }\n  ],\n  \"reviewer_id\": \"claude-opus-5-specreview\",\n  \"verdict\": \"accepted\",\n  \"fallback_reason\": \"\",\n  \"schema\": \"gzkit.acceptance.review.v1\"\n}\n```\n\nTwo scope notes: this envelope is the spec stage only, so the blocker `proof-3f67d2403b4b42ddabba84e25b8b815b lacks accepted quality review` remains open and is not addressed here. I listed and approved only `proof-3f67d240\u2026`; I read `proof-95c26e2e\u2026` as history but it carries input_digest `07585433\u2026`, a different subject, so it is neither examined-for-this-input nor approved. I made no file edits and initiated no OBPI operations.\n","stdout_truncated":false,"step":{"command":["claude","Read review-prompt.md and perform that bounded independent review. Return both requested JSON envelopes in raw text. Do not edit files or initiate OBPI operations.","--model","claude-opus-5","--effort","xhigh","--print","--output-format","text","--no-session-persistence","--tools","Read,Glob,Grep","--allowedTools","Read,Glob,Grep"],"name":"specreview"},"timestamp_utc":"2026-09-09T07:57:55Z"}