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FA-9666 / Configuration / Open access

Profile inheritance expansion: Parent values override child configuration · case 01

Parent values override child configuration.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The implementation substitutes for profile in chain: for for profile in reversed(chain):, so parent values override child configuration.

THE FAILURE

The implementation substitutes for profile in chain: for for profile in reversed(chain):, so parent values override child configuration.

Unsuccessful approach: The attempted repair substitutes for profile in chain[:1]:. Fixture 4 still yields {'x': 2} instead of {'x': 2, 'y': 4}.

Case contract

Resolve parent chains before child values, reject missing profiles, reject cycles, remove the reserved parent field, and allow explicit false values to override.

Why this case matters

An offline model of profile inheritance expansion, 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(profiles, name):
    chain = []
    seen = set()
    while name is not None:
        if name in seen: return 'cycle'
        if name not in profiles: return 'missing'
        seen.add(name)
        chain.append(profiles[name])
        name = profiles[name].get('parent')
    result = {}
    for profile in chain:
        result.update({k:v for k,v in profile.items() if k != 'parent'})
    return result
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({}, None), {})
check('fixture 2', solve({}, 'x'), 'missing')
check('fixture 3', solve({'a': {'x': 1}}, 'a'), {'x': 1})
check('fixture 4', solve({'a': {'x': 1, 'y': 4}, 'b': {'parent': 'a', 'x': 2}}, 'b'), {'x': 2, 'y': 4})
check('fixture 5', solve({'a': {'parent': 'b'}, 'b': {'parent': 'a'}}, 'a'), 'cycle')
check('fixture 6', solve({'a': {'x': True}, 'b': {'parent': 'a', 'x': False}}, 'b'), {'x': False})
check('fixture 7', solve({'a': {'parent': 'absent'}}, 'a'), 'missing')
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{}{}Passed
fixture 2missingmissingPassed
fixture 3{'x': 1}{'x': 1}Passed
fixture 4{'x': 1, 'y': 4}{'x': 2, 'y': 4}Failed
fixture 5cyclecyclePassed
fixture 6{'x': True}{'x': False}Failed
fixture 7missingmissingPassed

SHA-256 / ac64617f5e90cd88f86f8ad85eb8412f370b46eaa051f59b44d979bc63644d72

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(profiles, name):
    chain = []
    seen = set()
    while name is not None:
        if name in seen: return 'cycle'
        if name not in profiles: return 'missing'
        seen.add(name)
        chain.append(profiles[name])
        name = profiles[name].get('parent')
    result = {}
    for profile in chain[:1]:
        result.update({k:v for k,v in profile.items() if k != 'parent'})
    return result
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({}, None), {})
check('fixture 2', solve({}, 'x'), 'missing')
check('fixture 3', solve({'a': {'x': 1}}, 'a'), {'x': 1})
check('fixture 4', solve({'a': {'x': 1, 'y': 4}, 'b': {'parent': 'a', 'x': 2}}, 'b'), {'x': 2, 'y': 4})
check('fixture 5', solve({'a': {'parent': 'b'}, 'b': {'parent': 'a'}}, 'a'), 'cycle')
check('fixture 6', solve({'a': {'x': True}, 'b': {'parent': 'a', 'x': False}}, 'b'), {'x': False})
check('fixture 7', solve({'a': {'parent': 'absent'}}, 'a'), 'missing')
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{}{}Passed
fixture 2missingmissingPassed
fixture 3{'x': 1}{'x': 1}Passed
fixture 4{'x': 2}{'x': 2, 'y': 4}Failed
fixture 5cyclecyclePassed
fixture 6{'x': False}{'x': False}Passed
fixture 7missingmissingPassed

SHA-256 / 785c43d83031fbbfe54c6a50cb087de8f577b361707bb4714742871fc7c1f9e1

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 7 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

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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 2026-09-29T14:38:32.097773+00:00.

Case digest / 465dff1120f569846c7788ec589e9e4e411caed22a61a17e207cb440bdbd447c