FAILURE MAP
← Case archive

FA-9336 / Dependency resolution / Open access

Release candidate selection: Prereleases displace stable releases · case 01

Prereleases displace stable releases.

Verified by executionVariant 1 · 18 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The implementation substitutes True for not r['pre'], so prereleases displace stable releases.

THE FAILURE

The implementation substitutes True for not r['pre'], so prereleases displace stable releases.

Unsuccessful approach: The attempted repair substitutes r['pre']. Fixture 7 still yields (4, 0) instead of (2, 0).

Case contract

Choose the greatest compatible version; exclude yanked, prerelease, wrong-platform and below-minimum candidates. Return None if no candidates remain. Versions are integer tuples.

Why this case matters

An offline model of release candidate 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(releases, minimum, platform):
    items = [r for r in releases if not r['yanked']]
    items = [r for r in items if True]
    items = [r for r in items if r['platform'] in [platform, 'any']]
    items = [r for r in items if r['version'] >= minimum]
    return max((r['version'] for r in items), default=None)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve([], (0, 0), 'linux'), None)
check('fixture 2', solve([], (0, 0), 'win'), None)
check('fixture 3', solve([], (2, 0), 'linux'), None)
check('fixture 4', solve([], (2, 0), 'win'), None)
check('fixture 5', solve([], (6, 0), 'linux'), None)
check('fixture 6', solve([], (6, 0), 'win'), None)
check('fixture 7', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (0, 0), 'linux'), (2, 0))
check('fixture 8', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (0, 0), 'win'), (5, 0))
check('fixture 9', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (2, 0), 'linux'), (2, 0))
check('fixture 10', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (2, 0), 'win'), (5, 0))
check('fixture 11', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (6, 0), 'linux'), None)
check('fixture 12', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (6, 0), 'win'), None)
check('fixture 13', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (0, 0), 'linux'), (2, 0))
check('fixture 14', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (0, 0), 'win'), (2, 0))
check('fixture 15', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (2, 0), 'linux'), (2, 0))
check('fixture 16', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (2, 0), 'win'), (2, 0))
check('fixture 17', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (6, 0), 'linux'), None)
check('fixture 18', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (6, 0), 'win'), 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 fixtureActualExpectedOutcome
fixture 1NoneNonePassed
fixture 2NoneNonePassed
fixture 3NoneNonePassed
fixture 4NoneNonePassed
fixture 5NoneNonePassed
fixture 6NoneNonePassed
fixture 7[4, 0][2, 0]Failed
fixture 8[5, 0][5, 0]Passed
fixture 9[4, 0][2, 0]Failed
fixture 10[5, 0][5, 0]Passed
fixture 11NoneNonePassed
fixture 12NoneNonePassed
fixture 13[2, 0][2, 0]Passed
fixture 14[2, 0][2, 0]Passed
fixture 15[2, 0][2, 0]Passed
fixture 16[2, 0][2, 0]Passed
fixture 17NoneNonePassed
fixture 18NoneNonePassed

SHA-256 / 0ee4b59d97fe88b73005fe21689adbcdc2b3d766ecf1afb9713a28b6a4f65622

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(releases, minimum, platform):
    items = [r for r in releases if not r['yanked']]
    items = [r for r in items if r['pre']]
    items = [r for r in items if r['platform'] in [platform, 'any']]
    items = [r for r in items if r['version'] >= minimum]
    return max((r['version'] for r in items), default=None)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve([], (0, 0), 'linux'), None)
check('fixture 2', solve([], (0, 0), 'win'), None)
check('fixture 3', solve([], (2, 0), 'linux'), None)
check('fixture 4', solve([], (2, 0), 'win'), None)
check('fixture 5', solve([], (6, 0), 'linux'), None)
check('fixture 6', solve([], (6, 0), 'win'), None)
check('fixture 7', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (0, 0), 'linux'), (2, 0))
check('fixture 8', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (0, 0), 'win'), (5, 0))
check('fixture 9', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (2, 0), 'linux'), (2, 0))
check('fixture 10', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (2, 0), 'win'), (5, 0))
check('fixture 11', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (6, 0), 'linux'), None)
check('fixture 12', solve([{'version': (1, 0), 'yanked': False, 'pre': False, 'platform': 'any'}, {'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'linux'}, {'version': (3, 0), 'yanked': True, 'pre': False, 'platform': 'linux'}, {'version': (4, 0), 'yanked': False, 'pre': True, 'platform': 'linux'}, {'version': (5, 0), 'yanked': False, 'pre': False, 'platform': 'win'}], (6, 0), 'win'), None)
check('fixture 13', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (0, 0), 'linux'), (2, 0))
check('fixture 14', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (0, 0), 'win'), (2, 0))
check('fixture 15', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (2, 0), 'linux'), (2, 0))
check('fixture 16', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (2, 0), 'win'), (2, 0))
check('fixture 17', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (6, 0), 'linux'), None)
check('fixture 18', solve([{'version': (2, 0), 'yanked': False, 'pre': False, 'platform': 'any'}], (6, 0), 'win'), 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 fixtureActualExpectedOutcome
fixture 1NoneNonePassed
fixture 2NoneNonePassed
fixture 3NoneNonePassed
fixture 4NoneNonePassed
fixture 5NoneNonePassed
fixture 6NoneNonePassed
fixture 7[4, 0][2, 0]Failed
fixture 8None[5, 0]Failed
fixture 9[4, 0][2, 0]Failed
fixture 10None[5, 0]Failed
fixture 11NoneNonePassed
fixture 12NoneNonePassed
fixture 13None[2, 0]Failed
fixture 14None[2, 0]Failed
fixture 15None[2, 0]Failed
fixture 16None[2, 0]Failed
fixture 17NoneNonePassed
fixture 18NoneNonePassed

SHA-256 / c5f9545b795edcaae769dc6ba99c11bf506ac1aa96a52c696b56df67ca85de45

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 18 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.

Sign in to the archive ↗

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 2026-09-29T14:38:29.197649+00:00.

Case digest / 6174ddf9a2befc71492bd016c8a92727a0323c27f2517800b2151b51224a1603