{"abstract":"Packing assumes little-endian channel significance instead of the stated integer layout.","category":"Color encoding","checks":4,"contract":"Pack four integer bytes RGBA into an unsigned word with red as most significant byte and alpha as least significant byte.","contract_signature":"rgba","evaluation_group":"xg-pack-rgba-big-endian-word","failed_approach":"Correcting RGB byte order still discards alpha.","family":"xg-pack-rgba-big-endian-word","id":"FA-10596","implementations":{"attempt":{"sha256":"4a762fba071c64533cd7d857c91f1bac926597e8d3e559e13886b6fca41713ed","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(rgba):\n    return (rgba[0]<<24)|(rgba[1]<<16)|(rgba[2]<<8)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*([1, 2, 3, 4],)), 16909060)\ncheck('fixture 2', solve(*([0, 0, 0, 255],)), 255)\ncheck('fixture 3', solve(*([255, 0, 0, 0],)), 4278190080)\ncheck('fixture 4', solve(*([0, 0, 0, 0],)), 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":"3d71728d3211febd8faeef4c55c548472f14698867d499758f2b9a7ca475fe37","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(rgba):\n    return (rgba[3]<<24)|(rgba[2]<<16)|(rgba[1]<<8)|rgba[0]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*([1, 2, 3, 4],)), 16909060)\ncheck('fixture 2', solve(*([0, 0, 0, 255],)), 255)\ncheck('fixture 3', solve(*([255, 0, 0, 0],)), 4278190080)\ncheck('fixture 4', solve(*([0, 0, 0, 0],)), 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":" 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":"xg-pack-rgba-big-endian-word","generated_at":"2026-09-29T14:38:40.506231+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic software graphics stage with explicit channel and coordinate conventions; no hardware, device profile or API behavior is inferred.","root_cause":"Packing assumes little-endian channel significance instead of the stated integer layout.","sha256":"4133595e56be1cd15e2e310393cf906efaada96198f582c27954742380121633","title":"Pack rgba big endian word · 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":40.616,"exit_code":1,"observations":[{"actual":16909056,"check":"fixture 1","expected":16909060,"passed":false},{"actual":0,"check":"fixture 2","expected":255,"passed":false},{"actual":4278190080,"check":"fixture 3","expected":4278190080,"passed":true},{"actual":0,"check":"fixture 4","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 16909056, \"expected\": 16909060, \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": 0, \"expected\": 255, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 4278190080, \"expected\": 4278190080, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.995,"exit_code":1,"observations":[{"actual":67305985,"check":"fixture 1","expected":16909060,"passed":false},{"actual":4278190080,"check":"fixture 2","expected":255,"passed":false},{"actual":255,"check":"fixture 3","expected":4278190080,"passed":false},{"actual":0,"check":"fixture 4","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 67305985, \"expected\": 16909060, \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": 4278190080, \"expected\": 255, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 255, \"expected\": 4278190080, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": 0, \"expected\": 0, \"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."}}