{"abstract":"validation begins inside the embargo window.","category":"Dataset split isolation","checks":6,"contract":"Return IDs with time < start-gap from [id,time]; gap is a nonnegative integer and start is exclusive.","contract_signature":"records, start, gap","evaluation_group":"ds-embargo-gap","failed_approach":"A one-tick gap still leaks when embargo spans multiple ticks.","family":"w3-dataset-split-isolation-embargo-gap","id":"FA-97861","implementations":{"attempt":{"sha256":"b5694628bf54be0903384b8f33c7ed7635f8b28bb84ea5bb6b6e5dfc8b525867","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(records, start, gap):\n    return sorted(i for i,t in records if t<start-1)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('outside gap',solve([['a',N-4]],N,3),['a'])\ncheck('edge excluded',solve([['a',N-3]],N,3),[])\ncheck('inside excluded',solve([['a',N-1]],N,3),[])\ncheck('start excluded',solve([['a',N]],N,3),[])\ncheck('zero gap',solve([['a',N-1]],N,0),['a'])\ncheck('empty',solve([],N,2),[])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"86c9e586450ef7e4d5db0164d0a9b5d322c9a9e62dac02414c808fcfccd406c2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(records, start, gap):\n    return sorted(i for i,t in records if t<start)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('outside gap',solve([['a',N-4]],N,3),['a'])\ncheck('edge excluded',solve([['a',N-3]],N,3),[])\ncheck('inside excluded',solve([['a',N-1]],N,3),[])\ncheck('start excluded',solve([['a',N]],N,3),[])\ncheck('zero gap',solve([['a',N-1]],N,0),['a'])\ncheck('empty',solve([],N,2),[])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Inputs are small in-memory records with self-contained contracts; no claim is made about production sampling quality. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w3-dataset-split-isolation-embargo-gap","generated_at":"2026-09-30T16:48:06.688142+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This toy split allocator makes membership rules explicit for reproducible evaluation fixtures.","root_cause":"A temporal holdout leaves only a strict ordering constraint, not a safety gap.","sha256":"f2981c0b80f5e59c20ee3eed7f2ec71b6fac2a724fa0de45a8c7778bf6a71fd8","title":"Dataset split: validation begins inside the embargo window · case 01","variant":1,"variant_policy":"The fixture code references N, supplied as 1 through 5. Fixed boundary checks may repeat. These records share one mechanism and must remain together in evaluation splits.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":25.257,"exit_code":1,"observations":[{"actual":["a"],"check":"outside gap","expected":["a"],"passed":true},{"actual":["a"],"check":"edge excluded","expected":[],"passed":false},{"actual":[],"check":"inside excluded","expected":[],"passed":true},{"actual":[],"check":"start excluded","expected":[],"passed":true},{"actual":[],"check":"zero gap","expected":["a"],"passed":false},{"actual":[],"check":"empty","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"outside gap\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"edge excluded\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"inside excluded\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"start excluded\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"zero gap\", \"actual\": [], \"expected\": [\"a\"], \"passed\": false}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":32.543,"exit_code":1,"observations":[{"actual":["a"],"check":"outside gap","expected":["a"],"passed":true},{"actual":["a"],"check":"edge excluded","expected":[],"passed":false},{"actual":["a"],"check":"inside excluded","expected":[],"passed":false},{"actual":[],"check":"start excluded","expected":[],"passed":true},{"actual":["a"],"check":"zero gap","expected":["a"],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"outside gap\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"edge excluded\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"inside excluded\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"start excluded\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"zero gap\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}