FA-9491 / Dependency resolution / Open access
Package source selection: An index missing the package is selected · case 01
An index missing the package is selected.
ROOT CAUSE
The implementation substitutes True for name in s['packages'], so an index missing the package is selected.
VERIFIED REPAIR
Select only sources that contain the package.
Unsuccessful approach: The attempted repair substitutes name not in s['packages']. Fixture 2 still yields None instead of 'first'.
Case contract
Return first declared trusted nonmirror source containing the package, otherwise first trusted mirror containing it. Disabled and untrusted sources never participate.
Why this case matters
An offline model of package source 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(name, sources):
eligible = [s for s in sources if s['enabled']]
eligible = [s for s in eligible if s['trusted']]
eligible = [s for s in eligible if True]
primary = [s for s in eligible if not s['mirror']]
choices = primary or eligible
return choices[0]['name'] if choices else None
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('a', []), None)
check('fixture 2', solve('a', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}, {'name': 'bad', 'enabled': False, 'trusted': True, 'packages': ['a'], 'mirror': False}, {'name': 'untrusted', 'enabled': True, 'trusted': False, 'packages': ['a'], 'mirror': False}, {'name': 'first', 'enabled': True, 'trusted': True, 'packages': ['a', 'b'], 'mirror': False}, {'name': 'last', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': False}]), 'first')
check('fixture 3', solve('a', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}]), 'mirror')
check('fixture 4', solve('b', []), None)
check('fixture 5', solve('b', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}, {'name': 'bad', 'enabled': False, 'trusted': True, 'packages': ['a'], 'mirror': False}, {'name': 'untrusted', 'enabled': True, 'trusted': False, 'packages': ['a'], 'mirror': False}, {'name': 'first', 'enabled': True, 'trusted': True, 'packages': ['a', 'b'], 'mirror': False}, {'name': 'last', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': False}]), 'first')
check('fixture 6', solve('b', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}]), None)
check('fixture 7', solve('missing', []), None)
check('fixture 8', solve('missing', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}, {'name': 'bad', 'enabled': False, 'trusted': True, 'packages': ['a'], 'mirror': False}, {'name': 'untrusted', 'enabled': True, 'trusted': False, 'packages': ['a'], 'mirror': False}, {'name': 'first', 'enabled': True, 'trusted': True, 'packages': ['a', 'b'], 'mirror': False}, {'name': 'last', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': False}]), None)
check('fixture 9', solve('missing', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}]), 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 | first | first | Passed |
| fixture 3 | mirror | mirror | Passed |
| fixture 4 | None | None | Passed |
| fixture 5 | first | first | Passed |
| fixture 6 | mirror | None | Failed |
| fixture 7 | None | None | Passed |
| fixture 8 | first | None | Failed |
| fixture 9 | mirror | None | Failed |
SHA-256 / 78319212fa265959a407f28e408c6b0b6ec6817f5e9d4006ae6b76ece9d0c28e
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(name, sources):
eligible = [s for s in sources if s['enabled']]
eligible = [s for s in eligible if s['trusted']]
eligible = [s for s in eligible if name not in s['packages']]
primary = [s for s in eligible if not s['mirror']]
choices = primary or eligible
return choices[0]['name'] if choices else None
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('a', []), None)
check('fixture 2', solve('a', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}, {'name': 'bad', 'enabled': False, 'trusted': True, 'packages': ['a'], 'mirror': False}, {'name': 'untrusted', 'enabled': True, 'trusted': False, 'packages': ['a'], 'mirror': False}, {'name': 'first', 'enabled': True, 'trusted': True, 'packages': ['a', 'b'], 'mirror': False}, {'name': 'last', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': False}]), 'first')
check('fixture 3', solve('a', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}]), 'mirror')
check('fixture 4', solve('b', []), None)
check('fixture 5', solve('b', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}, {'name': 'bad', 'enabled': False, 'trusted': True, 'packages': ['a'], 'mirror': False}, {'name': 'untrusted', 'enabled': True, 'trusted': False, 'packages': ['a'], 'mirror': False}, {'name': 'first', 'enabled': True, 'trusted': True, 'packages': ['a', 'b'], 'mirror': False}, {'name': 'last', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': False}]), 'first')
check('fixture 6', solve('b', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}]), None)
check('fixture 7', solve('missing', []), None)
check('fixture 8', solve('missing', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}, {'name': 'bad', 'enabled': False, 'trusted': True, 'packages': ['a'], 'mirror': False}, {'name': 'untrusted', 'enabled': True, 'trusted': False, 'packages': ['a'], 'mirror': False}, {'name': 'first', 'enabled': True, 'trusted': True, 'packages': ['a', 'b'], 'mirror': False}, {'name': 'last', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': False}]), None)
check('fixture 9', solve('missing', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}]), 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 | first | Failed |
| fixture 3 | None | mirror | Failed |
| fixture 4 | None | None | Passed |
| fixture 5 | last | first | Failed |
| fixture 6 | mirror | None | Failed |
| fixture 7 | None | None | Passed |
| fixture 8 | first | None | Failed |
| fixture 9 | mirror | None | Failed |
SHA-256 / bda939620382d24e01191dbaac137123104b0831981f4150bb6e3afdf23b6517
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(name, sources):
eligible = [s for s in sources if s['enabled']]
eligible = [s for s in eligible if s['trusted']]
eligible = [s for s in eligible if name in s['packages']]
primary = [s for s in eligible if not s['mirror']]
choices = primary or eligible
return choices[0]['name'] if choices else None
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('a', []), None)
check('fixture 2', solve('a', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}, {'name': 'bad', 'enabled': False, 'trusted': True, 'packages': ['a'], 'mirror': False}, {'name': 'untrusted', 'enabled': True, 'trusted': False, 'packages': ['a'], 'mirror': False}, {'name': 'first', 'enabled': True, 'trusted': True, 'packages': ['a', 'b'], 'mirror': False}, {'name': 'last', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': False}]), 'first')
check('fixture 3', solve('a', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}]), 'mirror')
check('fixture 4', solve('b', []), None)
check('fixture 5', solve('b', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}, {'name': 'bad', 'enabled': False, 'trusted': True, 'packages': ['a'], 'mirror': False}, {'name': 'untrusted', 'enabled': True, 'trusted': False, 'packages': ['a'], 'mirror': False}, {'name': 'first', 'enabled': True, 'trusted': True, 'packages': ['a', 'b'], 'mirror': False}, {'name': 'last', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': False}]), 'first')
check('fixture 6', solve('b', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}]), None)
check('fixture 7', solve('missing', []), None)
check('fixture 8', solve('missing', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}, {'name': 'bad', 'enabled': False, 'trusted': True, 'packages': ['a'], 'mirror': False}, {'name': 'untrusted', 'enabled': True, 'trusted': False, 'packages': ['a'], 'mirror': False}, {'name': 'first', 'enabled': True, 'trusted': True, 'packages': ['a', 'b'], 'mirror': False}, {'name': 'last', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': False}]), None)
check('fixture 9', solve('missing', [{'name': 'mirror', 'enabled': True, 'trusted': True, 'packages': ['a'], 'mirror': True}]), 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 | first | first | Passed |
| fixture 3 | mirror | mirror | Passed |
| fixture 4 | None | None | Passed |
| fixture 5 | first | first | Passed |
| fixture 6 | None | None | Passed |
| fixture 7 | None | None | Passed |
| fixture 8 | None | None | Passed |
| fixture 9 | None | None | Passed |
SHA-256 / 3171b1b972fd8aef9871431f781cb62fc4e432f44930f71f1656c1c03d52263f
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 2026-09-29T14:38:30.411798+00:00.
Case digest / f9cbf44d3aba0f12d232bed71ed1aced4fe6482884eeee1c4505605d066df88a