{"abstract":"Delayed sensor samples enter the current fusion window.","category":"Sensor fusion consistency","checks":6,"contract":"Return IDs in input order whose acquisition timestamp is between now-window and now inclusive. Records are (ID, acquired, arrived); window is nonnegative.","contract_signature":"records, now, window","evaluation_group":"model-5878b383e2e1ed8b","failed_approach":"A one-sided age test accepts future acquisition times.","family":"z-sensor_fusion-acquisition-age","id":"FA-12041","implementations":{"attempt":{"sha256":"51c4a845c619c06464369406246ce5f85b7e0dbac36b7637d56e8d26a8f167c2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(records, now, window):\n    return [i for i,a,r in records if now-a <= window]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('delayed stale sample', solve([('a',N,10+N)],10+N,2), [])\ncheck('future clock sample', solve([('a',11+N,10+N)],10+N,2), [])\ncheck('old boundary', solve([('a',8+N,10+N)],10+N,2), ['a'])\ncheck('current acquisition', solve([('a',10+N,10+N)],10+N,0), ['a'])\ncheck('stable order', solve([('b',9+N,10+N),('a',10+N,10+N)],10+N,2), ['b','a'])\ncheck('empty window input', solve([],N,0), [])\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":"06d3a2c87595e3b972381d7e3a0f324bc64ed9ade1b4a1e61d71031298f8ddec","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(records, now, window):\n    return [i for i,a,r in records if 0 <= now-r <= window]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('delayed stale sample', solve([('a',N,10+N)],10+N,2), [])\ncheck('future clock sample', solve([('a',11+N,10+N)],10+N,2), [])\ncheck('old boundary', solve([('a',8+N,10+N)],10+N,2), ['a'])\ncheck('current acquisition', solve([('a',10+N,10+N)],10+N,0), ['a'])\ncheck('stable order', solve([('b',9+N,10+N),('a',10+N,10+N)],10+N,2), ['b','a'])\ncheck('empty window input', solve([],N,0), [])\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":"Exact small scalar or two-axis models; no nonlinear dynamics, numerical conditioning, or real sensor noise simulation. 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":"z-sensor_fusion-acquisition-age","generated_at":"2026-09-29T14:38:53.285774+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Deterministic sensor-fusion model isolating one consistency contract; no hardware or production estimator is simulated.","root_cause":"Freshness uses receipt time instead of acquisition time.","sha256":"ad887c70e8096c3248f0e21aa5d1e9c04144bb1af3ead4348f66610a5d555ae1","title":"Arrival time makes an old measurement look fresh · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":41.385,"exit_code":1,"observations":[{"actual":[],"check":"delayed stale sample","expected":[],"passed":true},{"actual":["a"],"check":"future clock sample","expected":[],"passed":false},{"actual":["a"],"check":"old boundary","expected":["a"],"passed":true},{"actual":["a"],"check":"current acquisition","expected":["a"],"passed":true},{"actual":["b","a"],"check":"stable order","expected":["b","a"],"passed":true},{"actual":[],"check":"empty window input","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"delayed stale sample\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"future clock sample\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"old boundary\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"current acquisition\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"stable order\", \"actual\": [\"b\", \"a\"], \"expected\": [\"b\", \"a\"], \"passed\": true}, {\"check\": \"empty window input\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.935,"exit_code":1,"observations":[{"actual":["a"],"check":"delayed stale sample","expected":[],"passed":false},{"actual":["a"],"check":"future clock sample","expected":[],"passed":false},{"actual":["a"],"check":"old boundary","expected":["a"],"passed":true},{"actual":["a"],"check":"current acquisition","expected":["a"],"passed":true},{"actual":["b","a"],"check":"stable order","expected":["b","a"],"passed":true},{"actual":[],"check":"empty window input","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"delayed stale sample\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"future clock sample\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"old boundary\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"current acquisition\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"stable order\", \"actual\": [\"b\", \"a\"], \"expected\": [\"b\", \"a\"], \"passed\": true}, {\"check\": \"empty window input\", \"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."}}