{"abstract":"An uncleared mix bus accumulates audio from the prior callback.","category":"Audio channel mixing","checks":4,"contract":"Mix one new block from equal-length input sources, discarding the previous bus contents. Previous length defines silence when no inputs exist.","evaluation_group":"xaud-mix-bus-clear-each-block","failed_approach":"Clearing without accumulating the current sources outputs silence.","family":"xaud-mix-bus-clear-each-block","id":"FA-10936","implementations":{"attempt":{"sha256":"10c901ef523df756e456d8c1e22eb9624cd9b787b3fbff4baf6a4b81a21a03a3","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(previous, inputs):\n    return [0]*len(previous)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([5, 5], [[1, 2], [3, 4]])),[4, 6])\ncheck('fixture 2',solve(*([5, 5], [])),[0, 0])\ncheck('fixture 3',solve(*([0], [[2]])),[2])\ncheck('fixture 4',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":"abe7bb4c7e62bcabc4a55c30ab85d8957ad0341d57555572d4c3a296ded8fad3","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(previous, inputs):\n    return [old+sum(frame) for old,frame in zip(previous,zip(*inputs))] if inputs else list(previous)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([5, 5], [[1, 2], [3, 4]])),[4, 6])\ncheck('fixture 2',solve(*([5, 5], [])),[0, 0])\ncheck('fixture 3',solve(*([0], [[2]])),[2])\ncheck('fixture 4',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":"529165862341ee68331159b4b0b3506e40f34a9524073cfc8b762c2e88bf3c22","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(previous, inputs):\n    return [sum(frame) for frame in zip(*inputs)] if inputs else [0]*len(previous)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([5, 5], [[1, 2], [3, 4]])),[4, 6])\ncheck('fixture 2',solve(*([5, 5], [])),[0, 0])\ncheck('fixture 3',solve(*([0], [[2]])),[2])\ncheck('fixture 4',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":" 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":"xaud-mix-bus-clear-each-block","generated_at":"2026-09-29T14:38:43.552983+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A pure Python local audio pipeline stage with explicit sample formats and frame conventions; no real-time device or signal-spectrum claims.","repair":"Apply the explicit PCM/playback contract: Mix one new block from equal-length input sources, discarding the previous bus contents. Previous length defines silence when no inputs exist.","root_cause":"An uncleared mix bus accumulates audio from the prior callback.","sha256":"959b9ab1ab026fbd1a0b4cfa17b54b08ec37fc466d8c0e1affb3aef9b6cbdc0a","title":"Mix bus clear each block · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":39.908,"exit_code":1,"observations":[{"actual":[0,0],"check":"fixture 1","expected":[4,6],"passed":false},{"actual":[0,0],"check":"fixture 2","expected":[0,0],"passed":true},{"actual":[0],"check":"fixture 3","expected":[2],"passed":false},{"actual":[],"check":"fixture 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [0, 0], \"expected\": [4, 6], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [0, 0], \"expected\": [0, 0], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [0], \"expected\": [2], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.144,"exit_code":1,"observations":[{"actual":[9,11],"check":"fixture 1","expected":[4,6],"passed":false},{"actual":[5,5],"check":"fixture 2","expected":[0,0],"passed":false},{"actual":[2],"check":"fixture 3","expected":[2],"passed":true},{"actual":[],"check":"fixture 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [9, 11], \"expected\": [4, 6], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [5, 5], \"expected\": [0, 0], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [2], \"expected\": [2], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.685,"exit_code":0,"observations":[{"actual":[4,6],"check":"fixture 1","expected":[4,6],"passed":true},{"actual":[0,0],"check":"fixture 2","expected":[0,0],"passed":true},{"actual":[2],"check":"fixture 3","expected":[2],"passed":true},{"actual":[],"check":"fixture 4","expected":[],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [4, 6], \"expected\": [4, 6], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [0, 0], \"expected\": [0, 0], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [2], \"expected\": [2], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}