{"abstract":"Evicting one media segment deletes initialization bytes needed by other segments.","category":"Streaming segment lifecycle","checks":4,"contract":"Segments are [ID,initialization-object ID]. Evict the named segment and collect init objects with no remaining references; preserve shared init data.","evaluation_group":"xmed-segment-eviction-retains-shared-init","failed_approach":"Never collecting init objects leaks unreferenced decoder initialization data.","family":"xmed-segment-eviction-retains-shared-init","id":"FA-11161","implementations":{"attempt":{"sha256":"f3f4c8b796ea2af5c6a8585bade6d553bb9c434817fd9fc35f05edbadb461d3d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(segments, remove, init_objects):\n    return [[x for x in segments if x[0]!=remove],list(init_objects)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[1, 'i'], [2, 'i']], 1, ['i'])),[[[2, 'i']], ['i']])\ncheck('fixture 2',solve(*([[1, 'i']], 1, ['i'])),[[], []])\ncheck('fixture 3',solve(*([[1, 'i'], [2, 'j']], 1, ['i', 'j'])),[[[2, 'j']], ['j']])\ncheck('fixture 4',solve(*([], 4, [])),[[], []])\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":"aadf6efa7c8f19181ba8930507451ac6aa7eb55dd1d9d7cd314b05af8d1c83a1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(segments, remove, init_objects):\n    return [[x for x in segments if x[0]!=remove],[]]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[1, 'i'], [2, 'i']], 1, ['i'])),[[[2, 'i']], ['i']])\ncheck('fixture 2',solve(*([[1, 'i']], 1, ['i'])),[[], []])\ncheck('fixture 3',solve(*([[1, 'i'], [2, 'j']], 1, ['i', 'j'])),[[[2, 'j']], ['j']])\ncheck('fixture 4',solve(*([], 4, [])),[[], []])\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":"e13fe481323981cd54fefa638a387c6091c5b3e9e9e0be0a2b4fc23b997cf2e7","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(segments, remove, init_objects):\n    return [[x for x in segments if x[0]!=remove],[i for i in init_objects if any(x[0]!=remove and x[1]==i for x in segments)]]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[1, 'i'], [2, 'i']], 1, ['i'])),[[[2, 'i']], ['i']])\ncheck('fixture 2',solve(*([[1, 'i']], 1, ['i'])),[[], []])\ncheck('fixture 3',solve(*([[1, 'i'], [2, 'j']], 1, ['i', 'j'])),[[[2, 'j']], ['j']])\ncheck('fixture 4',solve(*([], 4, [])),[[], []])\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":"xmed-segment-eviction-retains-shared-init","generated_at":"2026-09-29T14:38:45.525287+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic local media controller stage; metadata and downloaded data are supplied explicitly. No external player, service or codec is required.","repair":"Preserve the media contract: Segments are [ID,initialization-object ID]. Evict the named segment and collect init objects with no remaining references; preserve shared init data.","root_cause":"Evicting one media segment deletes initialization bytes needed by other segments.","sha256":"bfb2a2a8cfa0fe1eba67cf913e62199ab07e66a7778a55e2a0021cf0e967e5d5","title":"Segment eviction retains shared init · case 01","variant":1,"variant_policy":"The five numbered cases rerun the same authored boundary fixtures; they are reproducibility runs, not independent input variants.","verification":{"attempt":{"elapsed_ms":39.784,"exit_code":1,"observations":[{"actual":[[[2,"i"]],["i"]],"check":"fixture 1","expected":[[[2,"i"]],["i"]],"passed":true},{"actual":[[],["i"]],"check":"fixture 2","expected":[[],[]],"passed":false},{"actual":[[[2,"j"]],["i","j"]],"check":"fixture 3","expected":[[[2,"j"]],["j"]],"passed":false},{"actual":[[],[]],"check":"fixture 4","expected":[[],[]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[[2, \"i\"]], [\"i\"]], \"expected\": [[[2, \"i\"]], [\"i\"]], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [[], [\"i\"]], \"expected\": [[], []], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [[[2, \"j\"]], [\"i\", \"j\"]], \"expected\": [[[2, \"j\"]], [\"j\"]], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.419,"exit_code":1,"observations":[{"actual":[[[2,"i"]],[]],"check":"fixture 1","expected":[[[2,"i"]],["i"]],"passed":false},{"actual":[[],[]],"check":"fixture 2","expected":[[],[]],"passed":true},{"actual":[[[2,"j"]],[]],"check":"fixture 3","expected":[[[2,"j"]],["j"]],"passed":false},{"actual":[[],[]],"check":"fixture 4","expected":[[],[]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[[2, \"i\"]], []], \"expected\": [[[2, \"i\"]], [\"i\"]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[[2, \"j\"]], []], \"expected\": [[[2, \"j\"]], [\"j\"]], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.396,"exit_code":0,"observations":[{"actual":[[[2,"i"]],["i"]],"check":"fixture 1","expected":[[[2,"i"]],["i"]],"passed":true},{"actual":[[],[]],"check":"fixture 2","expected":[[],[]],"passed":true},{"actual":[[[2,"j"]],["j"]],"check":"fixture 3","expected":[[[2,"j"]],["j"]],"passed":true},{"actual":[[],[]],"check":"fixture 4","expected":[[],[]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[[2, \"i\"]], [\"i\"]], \"expected\": [[[2, \"i\"]], [\"i\"]], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[[2, \"j\"]], [\"j\"]], \"expected\": [[[2, \"j\"]], [\"j\"]], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}