{"abstract":"A manual appearance choice is overwritten by a subsequent system preference event.","category":"Client state","checks":6,"contract":"Appearance begins in system mode. A manual choice masks system changes without forgetting them; choosing system again reveals the latest system preference.","evaluation_group":"s3-client-state-system-preference-follow","failed_approach":"The partial repair still violates at least one explicit regression oracle.","family":"s3-client-state-system-preference-follow","id":"FA-24826","implementations":{"attempt":{"sha256":"1b1318c1e62d30cf970e8d3f0a48e0549e58678cd2e53c3015ba6066c7c442b2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events):\n    mode='light'\n    for kind,value in events:\n        if kind=='choose' and value!='system': mode=value\n    return mode\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('manual shields system event', solve([('choose','dark'),('system','light')]), 'dark')\ncheck('system mode follows', solve([('system','dark')]), 'dark')\ncheck('return to system', solve([('system','dark'),('choose','light'),('choose','system')]), 'dark')\ncheck('initial default', solve([]), 'light')\ncheck('manual empty preference valid', solve([('choose',''),('system','dark')]), '')\ncheck('parameterized repeated system events', solve([('choose','dark')]+[('system','light')]*N), 'dark')\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":"c262e5a18de55a292cb895aa2757d85254f438a6a345bd5aa22abfd3e9e42e60","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events):\n    return events[-1][1] if events else 'light'\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('manual shields system event', solve([('choose','dark'),('system','light')]), 'dark')\ncheck('system mode follows', solve([('system','dark')]), 'dark')\ncheck('return to system', solve([('system','dark'),('choose','light'),('choose','system')]), 'dark')\ncheck('initial default', solve([]), 'light')\ncheck('manual empty preference valid', solve([('choose',''),('system','dark')]), '')\ncheck('parameterized repeated system events', solve([('choose','dark')]+[('system','light')]*N), 'dark')\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":"1650ef6b19abf5f9669dc96b6e7e9b886187933ebea4232d9a7952dbc6eb4800","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events):\n    mode='system'; system='light'\n    for kind,value in events:\n        if kind=='choose': mode=value\n        elif kind=='system': system=value\n    return system if mode=='system' else mode\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('manual shields system event', solve([('choose','dark'),('system','light')]), 'dark')\ncheck('system mode follows', solve([('system','dark')]), 'dark')\ncheck('return to system', solve([('system','dark'),('choose','light'),('choose','system')]), 'dark')\ncheck('initial default', solve([]), 'light')\ncheck('manual empty preference valid', solve([('choose',''),('system','dark')]), '')\ncheck('parameterized repeated system events', solve([('choose','dark')]+[('system','light')]*N), 'dark')\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":"This models the stated application policy only; no browser or framework conformance is claimed. 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":"s3-client-state-system-preference-follow","generated_at":"2026-09-29T14:41:01.080782+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A bounded offline client-state transition with explicit lifecycle inputs.","repair":"Appearance begins in system mode. A manual choice masks system changes without forgetting them; choosing system again reveals the latest system preference.","root_cause":"The faulty implementation violates Appearance begins in system mode. A manual choice masks system changes without forgetting them; choosing system again reveals the latest system preference.","sha256":"538528f101eee9f89bd90081288c6264294cce9f4f4f14caa91a940640acf1ab","title":"A manual appearance choice is overwritten by a subsequent system preference event · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":40.993,"exit_code":1,"observations":[{"actual":"dark","check":"manual shields system event","expected":"dark","passed":true},{"actual":"light","check":"system mode follows","expected":"dark","passed":false},{"actual":"light","check":"return to system","expected":"dark","passed":false},{"actual":"light","check":"initial default","expected":"light","passed":true},{"actual":"","check":"manual empty preference valid","expected":"","passed":true},{"actual":"dark","check":"parameterized repeated system events","expected":"dark","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"manual shields system event\", \"actual\": \"dark\", \"expected\": \"dark\", \"passed\": true}, {\"check\": \"system mode follows\", \"actual\": \"light\", \"expected\": \"dark\", \"passed\": false}, {\"check\": \"return to system\", \"actual\": \"light\", \"expected\": \"dark\", \"passed\": false}, {\"check\": \"initial default\", \"actual\": \"light\", \"expected\": \"light\", \"passed\": true}, {\"check\": \"manual empty preference valid\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"parameterized repeated system events\", \"actual\": \"dark\", \"expected\": \"dark\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.011,"exit_code":1,"observations":[{"actual":"light","check":"manual shields system event","expected":"dark","passed":false},{"actual":"dark","check":"system mode follows","expected":"dark","passed":true},{"actual":"system","check":"return to system","expected":"dark","passed":false},{"actual":"light","check":"initial default","expected":"light","passed":true},{"actual":"dark","check":"manual empty preference valid","expected":"","passed":false},{"actual":"light","check":"parameterized repeated system events","expected":"dark","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"manual shields system event\", \"actual\": \"light\", \"expected\": \"dark\", \"passed\": false}, {\"check\": \"system mode follows\", \"actual\": \"dark\", \"expected\": \"dark\", \"passed\": true}, {\"check\": \"return to system\", \"actual\": \"system\", \"expected\": \"dark\", \"passed\": false}, {\"check\": \"initial default\", \"actual\": \"light\", \"expected\": \"light\", \"passed\": true}, {\"check\": \"manual empty preference valid\", \"actual\": \"dark\", \"expected\": \"\", \"passed\": false}, {\"check\": \"parameterized repeated system events\", \"actual\": \"light\", \"expected\": \"dark\", \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.813,"exit_code":0,"observations":[{"actual":"dark","check":"manual shields system event","expected":"dark","passed":true},{"actual":"dark","check":"system mode follows","expected":"dark","passed":true},{"actual":"dark","check":"return to system","expected":"dark","passed":true},{"actual":"light","check":"initial default","expected":"light","passed":true},{"actual":"","check":"manual empty preference valid","expected":"","passed":true},{"actual":"dark","check":"parameterized repeated system events","expected":"dark","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"manual shields system event\", \"actual\": \"dark\", \"expected\": \"dark\", \"passed\": true}, {\"check\": \"system mode follows\", \"actual\": \"dark\", \"expected\": \"dark\", \"passed\": true}, {\"check\": \"return to system\", \"actual\": \"dark\", \"expected\": \"dark\", \"passed\": true}, {\"check\": \"initial default\", \"actual\": \"light\", \"expected\": \"light\", \"passed\": true}, {\"check\": \"manual empty preference valid\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"parameterized repeated system events\", \"actual\": \"dark\", \"expected\": \"dark\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}