{"abstract":"Empty stop list incorrectly stops every output.","category":"Model output stopping rules","checks":6,"contract":"With no configured stop sequences, return all tokens and None. Otherwise stop at the earliest sequence occurrence.","contract_signature":"tokens, stops","evaluation_group":"w3-output-empty-stop","failed_approach":"Checking only a sequence’s first token mistakes a partial prefix for a complete marker.","family":"w3-model-output-stopping-rules-no-stop-empty","id":"FA-100831","implementations":{"attempt":{"sha256":"51b59bde34adf5a732ad88c63dcd6b3bc2d1907738770f2d5053a036ff1c92ac","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(tokens, stops):\n    for s in stops:\n        if s and s[0] in tokens:return tokens[:tokens.index(s[0])],0\n    return tokens,None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('empty configuration',solve(list(range(N)),[]),(list(range(N)),None))\ncheck('configured match',solve([1,8,2],[[8]]),([1],0))\ncheck('configured miss',solve([8,2],[[8,9]]),([8,2],None))\ncheck('empty output',solve([],[]),([],None))\ncheck('empty sequence ignored',solve([1],[[]]),([1],None))\ncheck('multi token match',solve([1,8,9],[[8,9]]),([1],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":"2da789f4a9ba6eb8491b73c806fa9b380a3755ab0924fdbb6a30133a670b1049","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(tokens, stops):\n    return ([],0) if not stops else (tokens,None)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('empty configuration',solve(list(range(N)),[]),(list(range(N)),None))\ncheck('configured match',solve([1,8,2],[[8]]),([1],0))\ncheck('configured miss',solve([8,2],[[8,9]]),([8,2],None))\ncheck('empty output',solve([],[]),([],None))\ncheck('empty sequence ignored',solve([1],[[]]),([1],None))\ncheck('multi token match',solve([1,8,9],[[8,9]]),([1],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 toy contract covers the supplied token records only; it does not claim compatibility with a particular model runtime or tokenizer. 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":"w3-model-output-stopping-rules-no-stop-empty","generated_at":"2026-09-30T16:48:40.055385+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic output-control model isolates one finish or streaming boundary from any particular runtime.","root_cause":"An empty configuration is treated as an immediate stop rather than no stopping condition.","sha256":"638d4ffbfbf1f53b158a7d3e06b8dc7842a1171d596c8e400ce7927fc07e71a7","title":"Output stopping: Empty stop list incorrectly stops every output · case 01","variant":1,"variant_policy":"The fixture code references N, supplied as 1 through 5. Fixed boundary checks may repeat. These records share one mechanism and must remain together in evaluation splits.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":27.526,"exit_code":1,"observations":[{"actual":[[0],null],"check":"empty configuration","expected":[[0],null],"passed":true},{"actual":[[1],0],"check":"configured match","expected":[[1],0],"passed":true},{"actual":[[],0],"check":"configured miss","expected":[[8,2],null],"passed":false},{"actual":[[],null],"check":"empty output","expected":[[],null],"passed":true},{"actual":[[1],null],"check":"empty sequence ignored","expected":[[1],null],"passed":true},{"actual":[[1],0],"check":"multi token match","expected":[[1],0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"empty configuration\", \"actual\": [[0], null], \"expected\": [[0], null], \"passed\": true}, {\"check\": \"configured match\", \"actual\": [[1], 0], \"expected\": [[1], 0], \"passed\": true}, {\"check\": \"configured miss\", \"actual\": [[], 0], \"expected\": [[8, 2], null], \"passed\": false}, {\"check\": \"empty output\", \"actual\": [[], null], \"expected\": [[], null], \"passed\": true}, {\"check\": \"empty sequence ignored\", \"actual\": [[1], null], \"expected\": [[1], null], \"passed\": true}, {\"check\": \"multi token match\", \"actual\": [[1], 0], \"expected\": [[1], 0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":29.031,"exit_code":1,"observations":[{"actual":[[],0],"check":"empty configuration","expected":[[0],null],"passed":false},{"actual":[[1,8,2],null],"check":"configured match","expected":[[1],0],"passed":false},{"actual":[[8,2],null],"check":"configured miss","expected":[[8,2],null],"passed":true},{"actual":[[],0],"check":"empty output","expected":[[],null],"passed":false},{"actual":[[1],null],"check":"empty sequence ignored","expected":[[1],null],"passed":true},{"actual":[[1,8,9],null],"check":"multi token match","expected":[[1],0],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"empty configuration\", \"actual\": [[], 0], \"expected\": [[0], null], \"passed\": false}, {\"check\": \"configured match\", \"actual\": [[1, 8, 2], null], \"expected\": [[1], 0], \"passed\": false}, {\"check\": \"configured miss\", \"actual\": [[8, 2], null], \"expected\": [[8, 2], null], \"passed\": true}, {\"check\": \"empty output\", \"actual\": [[], 0], \"expected\": [[], null], \"passed\": false}, {\"check\": \"empty sequence ignored\", \"actual\": [[1], null], \"expected\": [[1], null], \"passed\": true}, {\"check\": \"multi token match\", \"actual\": [[1, 8, 9], null], \"expected\": [[1], 0], \"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."}}