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FA-9811 / Configuration / Open access

Configuration schema upgrade: Legacy fields override canonical values · case 01

Legacy fields override canonical values.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The implementation substitutes 'timeout_ms' in result for 'timeout' not in result and 'timeout_ms' in result, so legacy fields override canonical values.

VERIFIED REPAIR

Migrate legacy values only when the canonical field is absent.

Unsuccessful approach: The attempted repair substitutes 'timeout' in result and 'timeout_ms' in result. Fixture 2 still yields {'schema': 2} instead of {'timeout': 1.5, 'schema': 2}.

Case contract

Rename timeout_ms to timeout only when new key is absent, remove deprecated timeout_ms, add schema version, preserve unknown settings, and scale legacy milliseconds to seconds.

Why this case matters

An offline model of configuration schema upgrade, suitable for testing build and release tooling without external services.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(config):
    result = dict(config)
    if 'timeout_ms' in result:
        result['timeout'] = result['timeout_ms'] / 1000
    result.pop('timeout_ms', None)
    result['schema'] = 2
    return result
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({}), {'schema': 2})
check('fixture 2', solve({'timeout_ms': 1500}), {'timeout': 1.5, 'schema': 2})
check('fixture 3', solve({'timeout_ms': 0}), {'timeout': 0.0, 'schema': 2})
check('fixture 4', solve({'timeout_ms': 1500, 'timeout': 9}), {'timeout': 9, 'schema': 2})
check('fixture 5', solve({'other': 3}), {'other': 3, 'schema': 2})
check('fixture 6', solve({'schema': 1, 'timeout': 2}), {'schema': 2, 'timeout': 2})
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
fixture 1{'schema': 2}{'schema': 2}Passed
fixture 2{'schema': 2, 'timeout': 1.5}{'schema': 2, 'timeout': 1.5}Passed
fixture 3{'schema': 2, 'timeout': 0.0}{'schema': 2, 'timeout': 0.0}Passed
fixture 4{'schema': 2, 'timeout': 1.5}{'schema': 2, 'timeout': 9}Failed
fixture 5{'other': 3, 'schema': 2}{'other': 3, 'schema': 2}Passed
fixture 6{'schema': 2, 'timeout': 2}{'schema': 2, 'timeout': 2}Passed

SHA-256 / e59815d432b03303bd7c3966dc133004d6ada4ff9539db812c815759b966170c

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(config):
    result = dict(config)
    if 'timeout' in result and 'timeout_ms' in result:
        result['timeout'] = result['timeout_ms'] / 1000
    result.pop('timeout_ms', None)
    result['schema'] = 2
    return result
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({}), {'schema': 2})
check('fixture 2', solve({'timeout_ms': 1500}), {'timeout': 1.5, 'schema': 2})
check('fixture 3', solve({'timeout_ms': 0}), {'timeout': 0.0, 'schema': 2})
check('fixture 4', solve({'timeout_ms': 1500, 'timeout': 9}), {'timeout': 9, 'schema': 2})
check('fixture 5', solve({'other': 3}), {'other': 3, 'schema': 2})
check('fixture 6', solve({'schema': 1, 'timeout': 2}), {'schema': 2, 'timeout': 2})
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
fixture 1{'schema': 2}{'schema': 2}Passed
fixture 2{'schema': 2}{'schema': 2, 'timeout': 1.5}Failed
fixture 3{'schema': 2}{'schema': 2, 'timeout': 0.0}Failed
fixture 4{'schema': 2, 'timeout': 1.5}{'schema': 2, 'timeout': 9}Failed
fixture 5{'other': 3, 'schema': 2}{'other': 3, 'schema': 2}Passed
fixture 6{'schema': 2, 'timeout': 2}{'schema': 2, 'timeout': 2}Passed

SHA-256 / 255975a2c48f9567546208a68d3837babfc1e044d8eeca473e7c9328dcadb044

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(config):
    result = dict(config)
    if 'timeout' not in result and 'timeout_ms' in result:
        result['timeout'] = result['timeout_ms'] / 1000
    result.pop('timeout_ms', None)
    result['schema'] = 2
    return result
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({}), {'schema': 2})
check('fixture 2', solve({'timeout_ms': 1500}), {'timeout': 1.5, 'schema': 2})
check('fixture 3', solve({'timeout_ms': 0}), {'timeout': 0.0, 'schema': 2})
check('fixture 4', solve({'timeout_ms': 1500, 'timeout': 9}), {'timeout': 9, 'schema': 2})
check('fixture 5', solve({'other': 3}), {'other': 3, 'schema': 2})
check('fixture 6', solve({'schema': 1, 'timeout': 2}), {'schema': 2, 'timeout': 2})
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
fixture 1{'schema': 2}{'schema': 2}Passed
fixture 2{'schema': 2, 'timeout': 1.5}{'schema': 2, 'timeout': 1.5}Passed
fixture 3{'schema': 2, 'timeout': 0.0}{'schema': 2, 'timeout': 0.0}Passed
fixture 4{'schema': 2, 'timeout': 9}{'schema': 2, 'timeout': 9}Passed
fixture 5{'other': 3, 'schema': 2}{'other': 3, 'schema': 2}Passed
fixture 6{'schema': 2, 'timeout': 2}{'schema': 2, 'timeout': 2}Passed

SHA-256 / b93781a57f210205aec15a5a5b156f6439925765d0b02c1bbd2455707a45094a

Verification & scope

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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:38:33.357683+00:00.

Case digest / f315c3e9eb070caf25d8103a1997614ca2745e0a370a57d1064beb230965d0b1