{"abstract":"Policy pinning violates retry transition semantics","category":"HTTP retries","checks":6,"contract":"configure(version,cap,statuses) sets current policy. begin(request) snapshots it with zero retries used; failure(request,status) uses that request snapshot and admits retry only for configured statuses below cap. update configuration affects later requests only. finish removes request; unknown failures report unknown. Return retry decisions with pinned policy version.","contract_signature":"events","evaluation_group":"s3-http_retries-policy-capture","failed_approach":"The attempted repair changes the faulty site to version,cap,statuses=(policy[0],current[1],current[2]) but still violates a regression oracle.","family":"s3-http_retries-policy-capture-policy-pinning","id":"FA-30206","implementations":{"attempt":{"sha256":"e6508f3597836e03f859e2e814d9de83b4e524437b4269eb9a2c190da7404f7c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events):\n    current=(0,0,()); requests={}; out=[]\n    for e in events:\n        if e[0]=='configure':\n            current=(e[1],e[2],tuple(e[3]))\n        elif e[0]=='begin':\n            if e[1] in requests: out.append('duplicate'); continue\n            requests[e[1]]=[current,0]\n        elif e[0]=='finish': requests.pop(e[1],None)\n        elif e[0]=='failure':\n            if e[1] not in requests: out.append('unknown'); continue\n            policy,used=requests[e[1]]\n            version,cap,statuses=(policy[0],current[1],current[2])\n            if e[2] not in statuses: out.append(['stop',version]); continue\n            if used>=cap: out.append(['exhausted',version]); continue\n            requests[e[1]][1]+=1\n            out.append(['retry',version])\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([]), [])\ncheck('1', solve([('failure','x',503)]), ['unknown'])\ncheck('2', solve([('configure',N,2,[503,429]),('begin','a'),('failure','a',503),('failure','a',429),('failure','a',503)]), [['retry',N],['retry',N],['exhausted',N]])\ncheck('3', solve([('configure',N,1,[503]),('begin','a'),('configure',N+1,0,[429]),('failure','a',429),('failure','a',503),('failure','a',503),('begin','b'),('failure','b',429)]), [['stop',N],['retry',N],['exhausted',N],['exhausted',N+1]])\ncheck('4', solve([('configure',N,1,[503]),('begin','a'),('failure','a',503),('begin','a'),('failure','a',503)]), [['retry',N],'duplicate',['exhausted',N]])\ncheck('5', solve([('configure',N,1,[503]),('begin','a'),('begin','b'),('finish','a'),('failure','a',503),('failure','b',503)]), ['unknown',['retry',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":"fe4bf794403bac290c2c238f0f048be4d5e6df35d4e88aaff28b988ab9f87d5e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events):\n    current=(0,0,()); requests={}; out=[]\n    for e in events:\n        if e[0]=='configure':\n            current=(e[1],e[2],tuple(e[3]))\n        elif e[0]=='begin':\n            if e[1] in requests: out.append('duplicate'); continue\n            requests[e[1]]=[current,0]\n        elif e[0]=='finish': requests.pop(e[1],None)\n        elif e[0]=='failure':\n            if e[1] not in requests: out.append('unknown'); continue\n            policy,used=requests[e[1]]\n            version,cap,statuses=current\n            if e[2] not in statuses: out.append(['stop',version]); continue\n            if used>=cap: out.append(['exhausted',version]); continue\n            requests[e[1]][1]+=1\n            out.append(['retry',version])\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([]), [])\ncheck('1', solve([('failure','x',503)]), ['unknown'])\ncheck('2', solve([('configure',N,2,[503,429]),('begin','a'),('failure','a',503),('failure','a',429),('failure','a',503)]), [['retry',N],['retry',N],['exhausted',N]])\ncheck('3', solve([('configure',N,1,[503]),('begin','a'),('configure',N+1,0,[429]),('failure','a',429),('failure','a',503),('failure','a',503),('begin','b'),('failure','b',429)]), [['stop',N],['retry',N],['exhausted',N],['exhausted',N+1]])\ncheck('4', solve([('configure',N,1,[503]),('begin','a'),('failure','a',503),('begin','a'),('failure','a',503)]), [['retry',N],'duplicate',['exhausted',N]])\ncheck('5', solve([('configure',N,1,[503]),('begin','a'),('begin','b'),('finish','a'),('failure','a',503),('failure','b',503)]), ['unknown',['retry',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":"Stipulated bounded simulator, not a complete HTTP implementation or a standards conformance claim. 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":"s3-http_retries-policy-capture-policy-pinning","generated_at":"2026-09-29T14:41:50.831104+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Offline deterministic model of HTTP request retries.","root_cause":"Policy pinning violates retry transition semantics","sha256":"0b72fe6fa881cde931830bdb3fb460e165b4e045ad82278949761eab5ada3d18","title":"In-flight retry policy capture: Policy pinning violates retry transition semantics · 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":46.462,"exit_code":1,"observations":[{"actual":[],"check":"0","expected":[],"passed":true},{"actual":["unknown"],"check":"1","expected":["unknown"],"passed":true},{"actual":[["retry",1],["retry",1],["exhausted",1]],"check":"2","expected":[["retry",1],["retry",1],["exhausted",1]],"passed":true},{"actual":[["exhausted",1],["stop",1],["stop",1],["exhausted",2]],"check":"3","expected":[["stop",1],["retry",1],["exhausted",1],["exhausted",2]],"passed":false},{"actual":[["retry",1],"duplicate",["exhausted",1]],"check":"4","expected":[["retry",1],"duplicate",["exhausted",1]],"passed":true},{"actual":["unknown",["retry",1]],"check":"5","expected":["unknown",["retry",1]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"1\", \"actual\": [\"unknown\"], \"expected\": [\"unknown\"], \"passed\": true}, {\"check\": \"2\", \"actual\": [[\"retry\", 1], [\"retry\", 1], [\"exhausted\", 1]], \"expected\": [[\"retry\", 1], [\"retry\", 1], [\"exhausted\", 1]], \"passed\": true}, {\"check\": \"3\", \"actual\": [[\"exhausted\", 1], [\"stop\", 1], [\"stop\", 1], [\"exhausted\", 2]], \"expected\": [[\"stop\", 1], [\"retry\", 1], [\"exhausted\", 1], [\"exhausted\", 2]], \"passed\": false}, {\"check\": \"4\", \"actual\": [[\"retry\", 1], \"duplicate\", [\"exhausted\", 1]], \"expected\": [[\"retry\", 1], \"duplicate\", [\"exhausted\", 1]], \"passed\": true}, {\"check\": \"5\", \"actual\": [\"unknown\", [\"retry\", 1]], \"expected\": [\"unknown\", [\"retry\", 1]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":44.325,"exit_code":1,"observations":[{"actual":[],"check":"0","expected":[],"passed":true},{"actual":["unknown"],"check":"1","expected":["unknown"],"passed":true},{"actual":[["retry",1],["retry",1],["exhausted",1]],"check":"2","expected":[["retry",1],["retry",1],["exhausted",1]],"passed":true},{"actual":[["exhausted",2],["stop",2],["stop",2],["exhausted",2]],"check":"3","expected":[["stop",1],["retry",1],["exhausted",1],["exhausted",2]],"passed":false},{"actual":[["retry",1],"duplicate",["exhausted",1]],"check":"4","expected":[["retry",1],"duplicate",["exhausted",1]],"passed":true},{"actual":["unknown",["retry",1]],"check":"5","expected":["unknown",["retry",1]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"1\", \"actual\": [\"unknown\"], \"expected\": [\"unknown\"], \"passed\": true}, {\"check\": \"2\", \"actual\": [[\"retry\", 1], [\"retry\", 1], [\"exhausted\", 1]], \"expected\": [[\"retry\", 1], [\"retry\", 1], [\"exhausted\", 1]], \"passed\": true}, {\"check\": \"3\", \"actual\": [[\"exhausted\", 2], [\"stop\", 2], [\"stop\", 2], [\"exhausted\", 2]], \"expected\": [[\"stop\", 1], [\"retry\", 1], [\"exhausted\", 1], [\"exhausted\", 2]], \"passed\": false}, {\"check\": \"4\", \"actual\": [[\"retry\", 1], \"duplicate\", [\"exhausted\", 1]], \"expected\": [[\"retry\", 1], \"duplicate\", [\"exhausted\", 1]], \"passed\": true}, {\"check\": \"5\", \"actual\": [\"unknown\", [\"retry\", 1]], \"expected\": [\"unknown\", [\"retry\", 1]], \"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."}}