FA-10161 / Deployment models / Open access

Rollback revision selection: A failed release becomes the rollback target · case 01

A failed release becomes the rollback target.

Verified by executionVariant 1 · 10 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The implementation substitutes True for r['success'], so a failed release becomes the rollback target.

VERIFIED REPAIR

Select only previously successful revisions.

Unsuccessful approach: The attempted repair substitutes not r['success']. Fixture 6 still yields 3 instead of 2.

Case contract

Choose the highest earlier revision that is successful, retained, compatible with current schema, and different from the active revision. Return None when no rollback target exists.

Why this case matters

An offline model of rollback revision selection, 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(revisions, active, schema):
    candidates = [r for r in revisions if r['number'] < active]
    candidates = [r for r in candidates if True]
    candidates = [r for r in candidates if r['retained']]
    candidates = [r for r in candidates if schema in r['schemas']]
    return max((r['number'] for r in candidates), default=None)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve([], 6, 1), None)
check('fixture 2', solve([], 7, 1), None)
check('fixture 3', solve([], 3, 1), None)
check('fixture 4', solve([], 6, 2), None)
check('fixture 5', solve([], 1, 1), None)
check('fixture 6', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 6, 1), 2)
check('fixture 7', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 7, 1), 6)
check('fixture 8', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 3, 1), 2)
check('fixture 9', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 6, 2), 5)
check('fixture 10', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 1, 1), None)
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 fixture	Actual	Expected	Outcome
fixture 1	`None`	`None`	Passed
fixture 2	`None`	`None`	Passed
fixture 3	`None`	`None`	Passed
fixture 4	`None`	`None`	Passed
fixture 5	`None`	`None`	Passed
fixture 6	`3`	`2`	Failed
fixture 7	`6`	`6`	Passed
fixture 8	`2`	`2`	Passed
fixture 9	`5`	`5`	Passed
fixture 10	`None`	`None`	Passed

SHA-256 / ed5ecf213838134d85c63ca2fdc64269571c5de187393d9b38cb22615289d814

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(revisions, active, schema):
    candidates = [r for r in revisions if r['number'] < active]
    candidates = [r for r in candidates if not r['success']]
    candidates = [r for r in candidates if r['retained']]
    candidates = [r for r in candidates if schema in r['schemas']]
    return max((r['number'] for r in candidates), default=None)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve([], 6, 1), None)
check('fixture 2', solve([], 7, 1), None)
check('fixture 3', solve([], 3, 1), None)
check('fixture 4', solve([], 6, 2), None)
check('fixture 5', solve([], 1, 1), None)
check('fixture 6', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 6, 1), 2)
check('fixture 7', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 7, 1), 6)
check('fixture 8', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 3, 1), 2)
check('fixture 9', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 6, 2), 5)
check('fixture 10', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 1, 1), None)
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 fixture	Actual	Expected	Outcome
fixture 1	`None`	`None`	Passed
fixture 2	`None`	`None`	Passed
fixture 3	`None`	`None`	Passed
fixture 4	`None`	`None`	Passed
fixture 5	`None`	`None`	Passed
fixture 6	`3`	`2`	Failed
fixture 7	`3`	`6`	Failed
fixture 8	`None`	`2`	Failed
fixture 9	`None`	`5`	Failed
fixture 10	`None`	`None`	Passed

SHA-256 / 47e10cea105952be875f37ecbfd7ec2917cf6697c260936bb7db8116e6ee8369

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(revisions, active, schema):
    candidates = [r for r in revisions if r['number'] < active]
    candidates = [r for r in candidates if r['success']]
    candidates = [r for r in candidates if r['retained']]
    candidates = [r for r in candidates if schema in r['schemas']]
    return max((r['number'] for r in candidates), default=None)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve([], 6, 1), None)
check('fixture 2', solve([], 7, 1), None)
check('fixture 3', solve([], 3, 1), None)
check('fixture 4', solve([], 6, 2), None)
check('fixture 5', solve([], 1, 1), None)
check('fixture 6', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 6, 1), 2)
check('fixture 7', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 7, 1), 6)
check('fixture 8', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 3, 1), 2)
check('fixture 9', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 6, 2), 5)
check('fixture 10', solve([{'number': 1, 'success': True, 'retained': True, 'schemas': [1, 2]}, {'number': 2, 'success': True, 'retained': True, 'schemas': [1]}, {'number': 3, 'success': False, 'retained': True, 'schemas': [1]}, {'number': 4, 'success': True, 'retained': False, 'schemas': [1]}, {'number': 5, 'success': True, 'retained': True, 'schemas': [2]}, {'number': 6, 'success': True, 'retained': True, 'schemas': [1]}], 1, 1), None)
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 fixture	Actual	Expected	Outcome
fixture 1	`None`	`None`	Passed
fixture 2	`None`	`None`	Passed
fixture 3	`None`	`None`	Passed
fixture 4	`None`	`None`	Passed
fixture 5	`None`	`None`	Passed
fixture 6	`2`	`2`	Passed
fixture 7	`6`	`6`	Passed
fixture 8	`2`	`2`	Passed
fixture 9	`5`	`5`	Passed
fixture 10	`None`	`None`	Passed

SHA-256 / 29d99f57b9376bb89a7ff176c84dbbeb2e7fa6d45dbed2fec8c13c36a65cd54a

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 2026-09-29T14:38:36.456021+00:00.

Case digest / e070319cf734d7221904a5a571719e3dc42adfde4f894fa1fddb9439f5ef1488