{"abstract":"One bidder wins two mutually exclusive package offers.","category":"Auction allocation rules","checks":6,"contract":"Process [bidder, item-list, value] offers by descending value, stable on ties. Accept only if its bidder has not won and none of its items are used. Return accepted original indices. This is a greedy policy, not optimal welfare.","evaluation_group":"model-8872b0007e5dac6a","failed_approach":"Keeping only the first bid per bidder before ranking throws away their higher priority offer.","family":"z-auction_matching-xor-packages","id":"FA-12716","implementations":{"attempt":{"sha256":"88582cd386f7f66f90cc1c910589ddfa784bf7f8b30e7308288d430cea83eb23","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(offers):\n    seen=set(); retained=[]\n    for i,o in enumerate(offers):\n     if o[0] not in seen: retained.append((i,o)); seen.add(o[0])\n    used=set(); result=[]\n    for i,(owner,items,value) in sorted(retained,key=lambda x:-x[1][2]):\n     if not used.intersection(items): result.append(i); used.update(items)\n    return result\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('later better exclusive offer', solve([['a',['x'],2],['a',['y'],10+N],['b',['x'],3]]), [1,2])\ncheck('disjoint same bidder', solve([['a',['x'],9],['a',['y'],8]]), [0])\ncheck('overlapping items', solve([['a',['x'],9],['b',['x'],8]]), [0])\ncheck('different owners disjoint', solve([['a',['x'],9],['b',['y'],8]]), [0,1])\ncheck('stable ties', solve([['a',['x'],8],['b',['x'],8]]), [0])\ncheck('no offers', solve([]), [])\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":"731ac6ff52b4fd8eb4c317eefb6ccdbca148ff68bb26bd7e752114f769b80bc8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(offers):\n    used=set(); result=[]\n    for i,(owner,items,value) in sorted(enumerate(offers),key=lambda x:-x[1][2]):\n     if not used.intersection(items): result.append(i); used.update(items)\n    return result\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('later better exclusive offer', solve([['a',['x'],2],['a',['y'],10+N],['b',['x'],3]]), [1,2])\ncheck('disjoint same bidder', solve([['a',['x'],9],['a',['y'],8]]), [0])\ncheck('overlapping items', solve([['a',['x'],9],['b',['x'],8]]), [0])\ncheck('different owners disjoint', solve([['a',['x'],9],['b',['y'],8]]), [0,1])\ncheck('stable ties', solve([['a',['x'],8],['b',['x'],8]]), [0])\ncheck('no offers', solve([]), [])\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":"ac70d785b93568f17d14fe3b92959355224d90b468adfa0e0ed2a1d8410848db","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(offers):\n    used=set(); owners=set(); result=[]\n    for i,(owner,items,value) in sorted(enumerate(offers),key=lambda x:-x[1][2]):\n     if owner not in owners and not used.intersection(items):\n      result.append(i); owners.add(owner); used.update(items)\n    return result\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('later better exclusive offer', solve([['a',['x'],2],['a',['y'],10+N],['b',['x'],3]]), [1,2])\ncheck('disjoint same bidder', solve([['a',['x'],9],['a',['y'],8]]), [0])\ncheck('overlapping items', solve([['a',['x'],9],['b',['x'],8]]), [0])\ncheck('different owners disjoint', solve([['a',['x'],9],['b',['y'],8]]), [0,1])\ncheck('stable ties', solve([['a',['x'],8],['b',['x'],8]]), [0])\ncheck('no offers', solve([]), [])\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":"Offline toy model with explicit integer inputs; no strategic behavior or real market execution. 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-auction_matching-xor-packages","generated_at":"2026-09-29T14:38:59.439333+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Deterministic teaching model for reviewing auction allocation software; not a representation of any venue or financial advice.","repair":"Implement the stated toy allocation contract directly: Process [bidder, item-list, value] offers by descending value, stable on ties. Accept only if its bidder has not won and none of its items are used. Return accepted original indices. This is a greedy policy, not optimal welfare.","root_cause":"Item disjointness is checked without bidder exclusivity.","sha256":"bc89b8926cc0b50a76daa6685f8cda7d72ccc248eff787386519dbe2ac79b5e8","title":"One bidder wins two mutually exclusive package offers · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":39.143,"exit_code":1,"observations":[{"actual":[2],"check":"later better exclusive offer","expected":[1,2],"passed":false},{"actual":[0],"check":"disjoint same bidder","expected":[0],"passed":true},{"actual":[0],"check":"overlapping items","expected":[0],"passed":true},{"actual":[0,1],"check":"different owners disjoint","expected":[0,1],"passed":true},{"actual":[0],"check":"stable ties","expected":[0],"passed":true},{"actual":[],"check":"no offers","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"later better exclusive offer\", \"actual\": [2], \"expected\": [1, 2], \"passed\": false}, {\"check\": \"disjoint same bidder\", \"actual\": [0], \"expected\": [0], \"passed\": true}, {\"check\": \"overlapping items\", \"actual\": [0], \"expected\": [0], \"passed\": true}, {\"check\": \"different owners disjoint\", \"actual\": [0, 1], \"expected\": [0, 1], \"passed\": true}, {\"check\": \"stable ties\", \"actual\": [0], \"expected\": [0], \"passed\": true}, {\"check\": \"no offers\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":43.481,"exit_code":1,"observations":[{"actual":[1,2],"check":"later better exclusive offer","expected":[1,2],"passed":true},{"actual":[0,1],"check":"disjoint same bidder","expected":[0],"passed":false},{"actual":[0],"check":"overlapping items","expected":[0],"passed":true},{"actual":[0,1],"check":"different owners disjoint","expected":[0,1],"passed":true},{"actual":[0],"check":"stable ties","expected":[0],"passed":true},{"actual":[],"check":"no offers","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"later better exclusive offer\", \"actual\": [1, 2], \"expected\": [1, 2], \"passed\": true}, {\"check\": \"disjoint same bidder\", \"actual\": [0, 1], \"expected\": [0], \"passed\": false}, {\"check\": \"overlapping items\", \"actual\": [0], \"expected\": [0], \"passed\": true}, {\"check\": \"different owners disjoint\", \"actual\": [0, 1], \"expected\": [0, 1], \"passed\": true}, {\"check\": \"stable ties\", \"actual\": [0], \"expected\": [0], \"passed\": true}, {\"check\": \"no offers\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":44.047,"exit_code":0,"observations":[{"actual":[1,2],"check":"later better exclusive offer","expected":[1,2],"passed":true},{"actual":[0],"check":"disjoint same bidder","expected":[0],"passed":true},{"actual":[0],"check":"overlapping items","expected":[0],"passed":true},{"actual":[0,1],"check":"different owners disjoint","expected":[0,1],"passed":true},{"actual":[0],"check":"stable ties","expected":[0],"passed":true},{"actual":[],"check":"no offers","expected":[],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"later better exclusive offer\", \"actual\": [1, 2], \"expected\": [1, 2], \"passed\": true}, {\"check\": \"disjoint same bidder\", \"actual\": [0], \"expected\": [0], \"passed\": true}, {\"check\": \"overlapping items\", \"actual\": [0], \"expected\": [0], \"passed\": true}, {\"check\": \"different owners disjoint\", \"actual\": [0, 1], \"expected\": [0, 1], \"passed\": true}, {\"check\": \"stable ties\", \"actual\": [0], \"expected\": [0], \"passed\": true}, {\"check\": \"no offers\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}