{"abstract":"Fallback messages use the requested locale plural rule.","category":"Localization message semantics","checks":6,"contract":"Catalogs contain key-to-branch maps for toy locales A and B. A selects one for 0 or 1; B only for 1. Resolve requested locale then B and select with the owning locale rule; missing keys return the key.","contract_signature":"catalogs, requested, key, n","evaluation_group":"model-6f66801ec88429c0","failed_approach":"Always using the default locale fixes fallback but corrupts messages actually found in the requested locale.","family":"z-localization-fallback-rule-owner","id":"FA-11771","implementations":{"attempt":{"sha256":"148a57dad7d837622ae772a755e638e0010823cb68c6b745e5a67d8b98008095","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(catalogs, requested, key, n):\n    owner = requested if key in catalogs.get(requested,{}) else 'B'\n    branches = catalogs.get(owner,{}).get(key)\n    if branches is None: return key\n    return branches['one' if n == 1 else 'other']\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fallback zero', solve({'B':{'k':{'one':'single','other':'many'}}},'A','k',0), 'many')\ncheck('local zero', solve({'A':{'k':{'one':'single','other':'many'}}},'A','k',0), 'single')\ncheck('local one', solve({'A':{'k':{'one':'single','other':'many'}}},'A','k',1), 'single')\ncheck('fallback one', solve({'B':{'k':{'one':'single','other':'many'}}},'A','k',1), 'single')\ncheck('many', solve({'B':{'k':{'one':'single','other':'many'}}},'A','k',N+1), 'many')\ncheck('missing', solve({},'A','k'+str(N),0), 'k'+str(N))\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":"92343acd1117906743aef8d9c3c9d6a2b29ab42f10467de5065350a9d1ebc621","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(catalogs, requested, key, n):\n    owner = requested if key in catalogs.get(requested,{}) else 'B'\n    branches = catalogs.get(owner,{}).get(key)\n    if branches is None: return key\n    return branches['one' if (n in (0,1) if requested == 'A' else n == 1) else 'other']\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fallback zero', solve({'B':{'k':{'one':'single','other':'many'}}},'A','k',0), 'many')\ncheck('local zero', solve({'A':{'k':{'one':'single','other':'many'}}},'A','k',0), 'single')\ncheck('local one', solve({'A':{'k':{'one':'single','other':'many'}}},'A','k',1), 'single')\ncheck('fallback one', solve({'B':{'k':{'one':'single','other':'many'}}},'A','k',1), 'single')\ncheck('many', solve({'B':{'k':{'one':'single','other':'many'}}},'A','k',N+1), 'many')\ncheck('missing', solve({},'A','k'+str(N),0), 'k'+str(N))\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":"Only the explicitly specified miniature locale/message rules are modeled. 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-localization-fallback-rule-owner","generated_at":"2026-09-29T14:38:50.888451+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This offline controlled message model isolates a localization decision; it does not implement a complete message-format or locale standard.","root_cause":"The requested locale rule is applied to branches belonging to a fallback locale.","sha256":"80b8f87aec83a2b97621666f7619dd158b83fb638cae4704f21c641c0ce96334","title":"Fallback messages use the requested locale plural rule · 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":38.461,"exit_code":1,"observations":[{"actual":"many","check":"fallback zero","expected":"many","passed":true},{"actual":"many","check":"local zero","expected":"single","passed":false},{"actual":"single","check":"local one","expected":"single","passed":true},{"actual":"single","check":"fallback one","expected":"single","passed":true},{"actual":"many","check":"many","expected":"many","passed":true},{"actual":"k1","check":"missing","expected":"k1","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fallback zero\", \"actual\": \"many\", \"expected\": \"many\", \"passed\": true}, {\"check\": \"local zero\", \"actual\": \"many\", \"expected\": \"single\", \"passed\": false}, {\"check\": \"local one\", \"actual\": \"single\", \"expected\": \"single\", \"passed\": true}, {\"check\": \"fallback one\", \"actual\": \"single\", \"expected\": \"single\", \"passed\": true}, {\"check\": \"many\", \"actual\": \"many\", \"expected\": \"many\", \"passed\": true}, {\"check\": \"missing\", \"actual\": \"k1\", \"expected\": \"k1\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.92,"exit_code":1,"observations":[{"actual":"single","check":"fallback zero","expected":"many","passed":false},{"actual":"single","check":"local zero","expected":"single","passed":true},{"actual":"single","check":"local one","expected":"single","passed":true},{"actual":"single","check":"fallback one","expected":"single","passed":true},{"actual":"many","check":"many","expected":"many","passed":true},{"actual":"k1","check":"missing","expected":"k1","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fallback zero\", \"actual\": \"single\", \"expected\": \"many\", \"passed\": false}, {\"check\": \"local zero\", \"actual\": \"single\", \"expected\": \"single\", \"passed\": true}, {\"check\": \"local one\", \"actual\": \"single\", \"expected\": \"single\", \"passed\": true}, {\"check\": \"fallback one\", \"actual\": \"single\", \"expected\": \"single\", \"passed\": true}, {\"check\": \"many\", \"actual\": \"many\", \"expected\": \"many\", \"passed\": true}, {\"check\": \"missing\", \"actual\": \"k1\", \"expected\": \"k1\", \"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."}}