{"abstract":"Bounded run packets silently discard overflow.","category":"Compression format semantics","checks":6,"contract":"Encode count repetitions as [count,symbol] packets with positive counts no greater than limit. Emit full limit packets then a nonzero remainder; count zero emits no packets.","contract_signature":"symbol, count, limit","evaluation_group":"model-654d0c24c08e4274","failed_approach":"Always emitting a remainder creates illegal zero-length packets on exact multiples.","family":"z-compression-bounded-run-packets","id":"FA-11636","implementations":{"attempt":{"sha256":"919e3139b92da08ac4cec0da2178dc1cab3b3caa5a5a5cf2264b4974b89c28a4","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(symbol, count, limit):\n    return [[limit,symbol]]*(count//limit)+[[count%limit,symbol]]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('overflow',solve('a',2*N+1,N),[[N,'a'],[N,'a'],[1,'a']] if N>1 else [[1,'a']]*3)\ncheck('exact multiple',solve('x',6,3),[[3,'x'],[3,'x']])\ncheck('empty',solve('x',0,3),[])\ncheck('under limit',solve('x',2,3),[[2,'x']])\ncheck('one packet',solve('x',3,3),[[3,'x']])\ncheck('unit limit',solve('b',2,1),[[1,'b'],[1,'b']])\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":"132b73c5614cadaaecda1acb31cd676443ce33add2db211189eb21385383761e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(symbol, count, limit):\n    return [[min(count,limit),symbol]] if count else []\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('overflow',solve('a',2*N+1,N),[[N,'a'],[N,'a'],[1,'a']] if N>1 else [[1,'a']]*3)\ncheck('exact multiple',solve('x',6,3),[[3,'x'],[3,'x']])\ncheck('empty',solve('x',0,3),[])\ncheck('under limit',solve('x',2,3),[[2,'x']])\ncheck('one packet',solve('x',3,3),[[3,'x']])\ncheck('unit limit',solve('b',2,1),[[1,'b'],[1,'b']])\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":"Controlled educational model, not a complete implementation of a production compression format. 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":"z-compression-bounded-run-packets","generated_at":"2026-09-29T14:38:49.707381+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A small offline codec model isolates a compression-specific failure without external files or libraries.","root_cause":"An encoder clamps a run to the packet count field maximum.","sha256":"10332b34d11664e7686c1a2ab5e74d3b2334dd62a7bcced3f5e2627ee11f5c30","title":"Bounded run packets silently discard overflow · 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":41.52,"exit_code":1,"observations":[{"actual":[[1,"a"],[1,"a"],[1,"a"],[0,"a"]],"check":"overflow","expected":[[1,"a"],[1,"a"],[1,"a"]],"passed":false},{"actual":[[3,"x"],[3,"x"],[0,"x"]],"check":"exact multiple","expected":[[3,"x"],[3,"x"]],"passed":false},{"actual":[[0,"x"]],"check":"empty","expected":[],"passed":false},{"actual":[[2,"x"]],"check":"under limit","expected":[[2,"x"]],"passed":true},{"actual":[[3,"x"],[0,"x"]],"check":"one packet","expected":[[3,"x"]],"passed":false},{"actual":[[1,"b"],[1,"b"],[0,"b"]],"check":"unit limit","expected":[[1,"b"],[1,"b"]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"overflow\", \"actual\": [[1, \"a\"], [1, \"a\"], [1, \"a\"], [0, \"a\"]], \"expected\": [[1, \"a\"], [1, \"a\"], [1, \"a\"]], \"passed\": false}, {\"check\": \"exact multiple\", \"actual\": [[3, \"x\"], [3, \"x\"], [0, \"x\"]], \"expected\": [[3, \"x\"], [3, \"x\"]], \"passed\": false}, {\"check\": \"empty\", \"actual\": [[0, \"x\"]], \"expected\": [], \"passed\": false}, {\"check\": \"under limit\", \"actual\": [[2, \"x\"]], \"expected\": [[2, \"x\"]], \"passed\": true}, {\"check\": \"one packet\", \"actual\": [[3, \"x\"], [0, \"x\"]], \"expected\": [[3, \"x\"]], \"passed\": false}, {\"check\": \"unit limit\", \"actual\": [[1, \"b\"], [1, \"b\"], [0, \"b\"]], \"expected\": [[1, \"b\"], [1, \"b\"]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":37.364,"exit_code":1,"observations":[{"actual":[[1,"a"]],"check":"overflow","expected":[[1,"a"],[1,"a"],[1,"a"]],"passed":false},{"actual":[[3,"x"]],"check":"exact multiple","expected":[[3,"x"],[3,"x"]],"passed":false},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[[2,"x"]],"check":"under limit","expected":[[2,"x"]],"passed":true},{"actual":[[3,"x"]],"check":"one packet","expected":[[3,"x"]],"passed":true},{"actual":[[1,"b"]],"check":"unit limit","expected":[[1,"b"],[1,"b"]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"overflow\", \"actual\": [[1, \"a\"]], \"expected\": [[1, \"a\"], [1, \"a\"], [1, \"a\"]], \"passed\": false}, {\"check\": \"exact multiple\", \"actual\": [[3, \"x\"]], \"expected\": [[3, \"x\"], [3, \"x\"]], \"passed\": false}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"under limit\", \"actual\": [[2, \"x\"]], \"expected\": [[2, \"x\"]], \"passed\": true}, {\"check\": \"one packet\", \"actual\": [[3, \"x\"]], \"expected\": [[3, \"x\"]], \"passed\": true}, {\"check\": \"unit limit\", \"actual\": [[1, \"b\"]], \"expected\": [[1, \"b\"], [1, \"b\"]], \"passed\": false}], \"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."}}