{"abstract":"The erased coverage is retained instead of its complement.","category":"Raster compositing","checks":4,"contract":"Destination is premultiplied RGBA. Destination-out retains each channel times one minus normalized source alpha.","contract_signature":"destination, source_alpha","evaluation_group":"xg-destination-out-preserves-uncovered","failed_approach":"Erasing only alpha leaves invalid color in transparent pixels.","family":"xg-destination-out-preserves-uncovered","id":"FA-10561","implementations":{"attempt":{"sha256":"768874e7e3fa234c2c11f419deadb306df82be702c1ea7e71edb18dad4340f35","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(destination, source_alpha):\n    return destination[:3]+[destination[3]*(1-source_alpha)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*([0.5, 0.25, 0, 0.5], 0.25)), [0.375, 0.1875, 0, 0.375])\ncheck('fixture 2', solve(*([1, 1, 1, 1], 1)), [0, 0, 0, 0])\ncheck('fixture 3', solve(*([0.5, 0.5, 0.5, 0.5], 0)), [0.5, 0.5, 0.5, 0.5])\ncheck('fixture 4', solve(*([0, 0, 0, 0], 0.5)), [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":"773d62655acf00b0c44cb3eaec31c03676536d1835bb934779081367f02eda43","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(destination, source_alpha):\n    return [x*source_alpha for x in destination]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*([0.5, 0.25, 0, 0.5], 0.25)), [0.375, 0.1875, 0, 0.375])\ncheck('fixture 2', solve(*([1, 1, 1, 1], 1)), [0, 0, 0, 0])\ncheck('fixture 3', solve(*([0.5, 0.5, 0.5, 0.5], 0)), [0.5, 0.5, 0.5, 0.5])\ncheck('fixture 4', solve(*([0, 0, 0, 0], 0.5)), [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-destination-out-preserves-uncovered","generated_at":"2026-09-29T14:38:40.046031+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":"The erased coverage is retained instead of its complement.","sha256":"aafccf9bf1f89779d812f98cf1cdf84afa623dfb0bf72bba7acdca835a9317f9","title":"Destination out preserves uncovered · 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":40.198,"exit_code":1,"observations":[{"actual":[0.5,0.25,0,0.375],"check":"fixture 1","expected":[0.375,0.1875,0,0.375],"passed":false},{"actual":[1,1,1,0],"check":"fixture 2","expected":[0,0,0,0],"passed":false},{"actual":[0.5,0.5,0.5,0.5],"check":"fixture 3","expected":[0.5,0.5,0.5,0.5],"passed":true},{"actual":[0,0,0,0.0],"check":"fixture 4","expected":[0,0,0,0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [0.5, 0.25, 0, 0.375], \"expected\": [0.375, 0.1875, 0, 0.375], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [1, 1, 1, 0], \"expected\": [0, 0, 0, 0], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [0.5, 0.5, 0.5, 0.5], \"expected\": [0.5, 0.5, 0.5, 0.5], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0, 0, 0, 0.0], \"expected\": [0, 0, 0, 0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.316,"exit_code":1,"observations":[{"actual":[0.125,0.0625,0.0,0.125],"check":"fixture 1","expected":[0.375,0.1875,0,0.375],"passed":false},{"actual":[1,1,1,1],"check":"fixture 2","expected":[0,0,0,0],"passed":false},{"actual":[0.0,0.0,0.0,0.0],"check":"fixture 3","expected":[0.5,0.5,0.5,0.5],"passed":false},{"actual":[0.0,0.0,0.0,0.0],"check":"fixture 4","expected":[0,0,0,0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [0.125, 0.0625, 0.0, 0.125], \"expected\": [0.375, 0.1875, 0, 0.375], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [1, 1, 1, 1], \"expected\": [0, 0, 0, 0], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [0.0, 0.0, 0.0, 0.0], \"expected\": [0.5, 0.5, 0.5, 0.5], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [0.0, 0.0, 0.0, 0.0], \"expected\": [0, 0, 0, 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."}}