{"abstract":"A specimen is reported at its destination despite a broken handoff chain.","category":"Scientific pipeline provenance","checks":7,"contract":"Given initial specimen holder and chronological [sender,recipient] handoffs, return final holder if every sender equals the preceding holder; otherwise None. Empty history preserves initial holder. Names are nonempty strings; self handoffs are permitted.","evaluation_group":"model-950bf48b9e0c7704","failed_approach":"Checking only the initial sender misses a broken later handoff.","family":"z-scientific_pipelines-custody-handoff","id":"FA-11916","implementations":{"attempt":{"sha256":"4243698974c83e76089ce59267bdd16fd64c49129c9787abf06de9d6c9b634db","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(initial, handoffs):\n    if handoffs and handoffs[0][0]!=initial: return None\n    return handoffs[-1][1] if handoffs else initial\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nlab='lab'+str(N)\ncheck('later sender mismatch', solve('collector', [('collector',lab),('stranger','archive')]), None)\ncheck('initial sender mismatch', solve('collector', [('stranger',lab)]), None)\ncheck('continuous chain', solve('collector', [('collector',lab),(lab,'archive')]), 'archive')\ncheck('no transfer', solve(lab, []), lab)\ncheck('self transfer', solve(lab, [(lab,lab)]), lab)\ncheck('return to origin', solve('collector', [('collector',lab),(lab,'collector')]), 'collector')\ncheck('invalid middle cannot be healed', solve('collector', [('collector',lab),('other','archive'),('archive',lab)]), None)\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":"922b788a383cb27c6b338fabbb546d8dacb864f3d108961ced615c70cf8ea6c5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(initial, handoffs):\n    return handoffs[-1][1] if handoffs else initial\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nlab='lab'+str(N)\ncheck('later sender mismatch', solve('collector', [('collector',lab),('stranger','archive')]), None)\ncheck('initial sender mismatch', solve('collector', [('stranger',lab)]), None)\ncheck('continuous chain', solve('collector', [('collector',lab),(lab,'archive')]), 'archive')\ncheck('no transfer', solve(lab, []), lab)\ncheck('self transfer', solve(lab, [(lab,lab)]), lab)\ncheck('return to origin', solve('collector', [('collector',lab),(lab,'collector')]), 'collector')\ncheck('invalid middle cannot be healed', solve('collector', [('collector',lab),('other','archive'),('archive',lab)]), None)\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"},"fixed":{"sha256":"34d17063505ab703fb1d9f34480a1609863383f06302e22b4610a722f4d16d7c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(initial, handoffs):\n    holder=initial\n    for sender,recipient in handoffs:\n        if sender!=holder: return None\n        holder=recipient\n    return holder\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nlab='lab'+str(N)\ncheck('later sender mismatch', solve('collector', [('collector',lab),('stranger','archive')]), None)\ncheck('initial sender mismatch', solve('collector', [('stranger',lab)]), None)\ncheck('continuous chain', solve('collector', [('collector',lab),(lab,'archive')]), 'archive')\ncheck('no transfer', solve(lab, []), lab)\ncheck('self transfer', solve(lab, [(lab,lab)]), lab)\ncheck('return to origin', solve('collector', [('collector',lab),(lab,'collector')]), 'collector')\ncheck('invalid middle cannot be healed', solve('collector', [('collector',lab),('other','archive'),('archive',lab)]), None)\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":"Symbolic in-memory model only; not instrument safety guidance or a production scientific validation. 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-scientific_pipelines-custody-handoff","generated_at":"2026-09-29T14:38:52.186735+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic offline model of scientific specimen processing and provenance; explicit fixtures test the stated bookkeeping or processing acceptance rule.","repair":"Walk signed handoffs in order and require each sender to be the current holder; reject the entire inconsistent ledger.","root_cause":"Only the final recipient is retained, discarding continuity of custody.","sha256":"ad1ae1698fad0648125fb3908e76a6a20cff79d47d5e3997bb0f3773604dfa98","title":"A specimen custody ledger accepts a transfer from a noncustodian · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":41.486,"exit_code":1,"observations":[{"actual":"archive","check":"later sender mismatch","expected":null,"passed":false},{"actual":null,"check":"initial sender mismatch","expected":null,"passed":true},{"actual":"archive","check":"continuous chain","expected":"archive","passed":true},{"actual":"lab1","check":"no transfer","expected":"lab1","passed":true},{"actual":"lab1","check":"self transfer","expected":"lab1","passed":true},{"actual":"collector","check":"return to origin","expected":"collector","passed":true},{"actual":"lab1","check":"invalid middle cannot be healed","expected":null,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"later sender mismatch\", \"actual\": \"archive\", \"expected\": null, \"passed\": false}, {\"check\": \"initial sender mismatch\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"continuous chain\", \"actual\": \"archive\", \"expected\": \"archive\", \"passed\": true}, {\"check\": \"no transfer\", \"actual\": \"lab1\", \"expected\": \"lab1\", \"passed\": true}, {\"check\": \"self transfer\", \"actual\": \"lab1\", \"expected\": \"lab1\", \"passed\": true}, {\"check\": \"return to origin\", \"actual\": \"collector\", \"expected\": \"collector\", \"passed\": true}, {\"check\": \"invalid middle cannot be healed\", \"actual\": \"lab1\", \"expected\": null, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.555,"exit_code":1,"observations":[{"actual":"archive","check":"later sender mismatch","expected":null,"passed":false},{"actual":"lab1","check":"initial sender mismatch","expected":null,"passed":false},{"actual":"archive","check":"continuous chain","expected":"archive","passed":true},{"actual":"lab1","check":"no transfer","expected":"lab1","passed":true},{"actual":"lab1","check":"self transfer","expected":"lab1","passed":true},{"actual":"collector","check":"return to origin","expected":"collector","passed":true},{"actual":"lab1","check":"invalid middle cannot be healed","expected":null,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"later sender mismatch\", \"actual\": \"archive\", \"expected\": null, \"passed\": false}, {\"check\": \"initial sender mismatch\", \"actual\": \"lab1\", \"expected\": null, \"passed\": false}, {\"check\": \"continuous chain\", \"actual\": \"archive\", \"expected\": \"archive\", \"passed\": true}, {\"check\": \"no transfer\", \"actual\": \"lab1\", \"expected\": \"lab1\", \"passed\": true}, {\"check\": \"self transfer\", \"actual\": \"lab1\", \"expected\": \"lab1\", \"passed\": true}, {\"check\": \"return to origin\", \"actual\": \"collector\", \"expected\": \"collector\", \"passed\": true}, {\"check\": \"invalid middle cannot be healed\", \"actual\": \"lab1\", \"expected\": null, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.566,"exit_code":0,"observations":[{"actual":null,"check":"later sender mismatch","expected":null,"passed":true},{"actual":null,"check":"initial sender mismatch","expected":null,"passed":true},{"actual":"archive","check":"continuous chain","expected":"archive","passed":true},{"actual":"lab1","check":"no transfer","expected":"lab1","passed":true},{"actual":"lab1","check":"self transfer","expected":"lab1","passed":true},{"actual":"collector","check":"return to origin","expected":"collector","passed":true},{"actual":null,"check":"invalid middle cannot be healed","expected":null,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"later sender mismatch\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"initial sender mismatch\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"continuous chain\", \"actual\": \"archive\", \"expected\": \"archive\", \"passed\": true}, {\"check\": \"no transfer\", \"actual\": \"lab1\", \"expected\": \"lab1\", \"passed\": true}, {\"check\": \"self transfer\", \"actual\": \"lab1\", \"expected\": \"lab1\", \"passed\": true}, {\"check\": \"return to origin\", \"actual\": \"collector\", \"expected\": \"collector\", \"passed\": true}, {\"check\": \"invalid middle cannot be healed\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}