FA-86111 / Game economy crafting balance / Open access
Magic find loot roll: Magic find skips legendary items · case 01
Magic find boosts rares but not legendaries.
ROOT CAUSE
The boost applies only to the rare tier instead of every non-common tier.
VERIFIED REPAIR
Restore `if rarity != 'common':` at the magic find scope step.
Unsuccessful approach: Skipping non-positive magic find ignores curse penalties.
Case contract
table = [[item, rarity, weight], ...]. Non-common weights become floor(w*(100+mf)/100) (mf may be negative). With total boosted weight T (None if 0), target = floor(roll*T/10000) for roll 0..9999; return the first item whose cumulative boosted weight exceeds target.
Why this case matters
Game economies leak or destroy currency when one crafting or pricing rule is off by one boundary, rounding stage or state update; the defect is observable in exact integer outcomes.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(table, roll, magic_find):
weights = []
for item, rarity, w in table:
if rarity == 'rare':
w = w * (100 + magic_find) // 100
weights.append(w)
total = sum(weights)
if total == 0:
return None
target = roll * total // 10000
acc = 0
for (item, rarity, w0), w in zip(table, weights):
acc += w
if target < acc:
return item
return None
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('fault site magic find scope #1',
[[['i0', 'legendary', 10], ['i1', 'rare', 29], ['i2', 'common', 95]], 827, 100],
'i0'),
('fault site magic find scope #2',
[[['i0', 'rare', 2], ['i1', 'common', 10], ['i2', 'legendary', 10], ['i3', 'rare', 10]], 5000, 250],
'i2'),
('partial repair boundary #1', [[['i0', 'rare', 1], ['i1', 'rare', 2]], 1, -50], 'i1'),
('regression magic find scope #1',
[[['i0', 'legendary', 10],
['i1', 'common', 0],
['i2', 'common', 2],
['i3', 'rare', 0],
['i4', 'common', 10]],
5000,
-50],
'i4'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'rare', 50]], 9999, 50], 'i1')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('regression magic find scope #1',
[[['i0', 'legendary', 10],
['i1', 'common', 0],
['i2', 'common', 2],
['i3', 'rare', 0],
['i4', 'common', 10]],
5000,
-50],
'i4'),
('fault site magic find scope #1',
[[['i0', 'common', 10], ['i1', 'common', 5], ['i2', 'legendary', 2], ['i3', 'legendary', 1]], 4998, 181],
'i1'),
('regression magic find scope #2',
[[['i0', 'rare', 5], ['i1', 'rare', 5], ['i2', 'common', 1], ['i3', 'rare', 0], ['i4', 'legendary', 1]],
9999,
-50],
'i2'),
('regression magic find scope #3',
[[['i0', 'common', 10], ['i1', 'common', 1], ['i2', 'legendary', 50], ['i3', 'legendary', 1]], 9999, -50],
'i2'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'rare', 50]], 9999, 50], 'i1')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('regression magic find scope #1',
[[['i0', 'rare', 5], ['i1', 'rare', 5], ['i2', 'common', 1], ['i3', 'rare', 0], ['i4', 'legendary', 1]],
9999,
-50],
'i2'),
('regression magic find scope #2',
[[['i0', 'common', 10], ['i1', 'common', 1], ['i2', 'legendary', 50], ['i3', 'legendary', 1]], 9999, -50],
'i2'),
('regression magic find scope #3',
[[['i0', 'legendary', 10], ['i1', 'rare', 10], ['i2', 'common', 5], ['i3', 'rare', 10], ['i4', 'rare', 1]],
5000,
-66],
'i2'),
('regression magic find scope #4', [[['i0', 'legendary', 1]], 5000, -50], None),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'rare', 50]], 9999, 50], 'i1')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('fault site magic find scope #1',
[[['i0', 'legendary', 41], ['i1', 'rare', 1], ['i2', 'rare', 5], ['i3', 'common', 30]], 5000, 110],
'i0'),
('fault site magic find scope #2',
[[['i0', 'legendary', 55], ['i1', 'common', 50], ['i2', 'legendary', 2], ['i3', 'common', 55]], 5000, 100],
'i0'),
('regression magic find scope #1', [[['i0', 'legendary', 1]], 5000, -50], None),
('regression magic find scope #2',
[[['i0', 'legendary', 1], ['i1', 'common', 1], ['i2', 'legendary', 50]], 1, -50],
'i1'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'common', 50], ['i2', 'legendary', 50]], 793, -50], 'i0')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('fault site magic find scope #1',
[[['i0', 'common', 2], ['i1', 'legendary', 1], ['i2', 'legendary', 2], ['i3', 'legendary', 3]], 3114, 100],
'i2'),
('regression magic find scope #1',
[[['i0', 'legendary', 10], ['i1', 'rare', 10], ['i2', 'common', 5], ['i3', 'rare', 10], ['i4', 'rare', 1]],
5000,
-66],
'i2'),
('partial repair boundary #1',
[[['i0', 'common', 5], ['i1', 'legendary', 2], ['i2', 'rare', 1], ['i3', 'rare', 5], ['i4', 'common', 0]],
5000,
-50],
'i0'),
('regression magic find scope #2',
[[['i0', 'legendary', 1], ['i1', 'rare', 2], ['i2', 'legendary', 5], ['i3', 'rare', 5]], 0, -16],
'i1'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'rare', 1], ['i1', 'common', 10], ['i2', 'legendary', 93]], 0, 100], 'i0')]]
for label, args, expected in cases[N-1]:
check(label, solve(*args), expected)
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 |
|---|---|---|---|
| curse lowers rare #1 | rock | rock | Passed |
| fault site magic find scope #1 | i1 | i0 | Failed |
| fault site magic find scope #2 | i3 | i2 | Failed |
| partial repair boundary #1 | i1 | i1 | Passed |
| regression magic find scope #1 | i2 | i4 | Failed |
| legendary boosted #1 | crown | crown | Passed |
| zero weight entry skipped #1 | c | c | Passed |
| control #1 | i1 | i1 | Passed |
SHA-256 / c43bd94e40e5539d092a49981cd9b155f6300c5ed356f9f61d2bb4d58320bb3d
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(table, roll, magic_find):
weights = []
for item, rarity, w in table:
if rarity != 'common' and magic_find > 0:
w = w * (100 + magic_find) // 100
weights.append(w)
total = sum(weights)
if total == 0:
return None
target = roll * total // 10000
acc = 0
for (item, rarity, w0), w in zip(table, weights):
acc += w
if target < acc:
return item
return None
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('fault site magic find scope #1',
[[['i0', 'legendary', 10], ['i1', 'rare', 29], ['i2', 'common', 95]], 827, 100],
'i0'),
('fault site magic find scope #2',
[[['i0', 'rare', 2], ['i1', 'common', 10], ['i2', 'legendary', 10], ['i3', 'rare', 10]], 5000, 250],
'i2'),
('partial repair boundary #1', [[['i0', 'rare', 1], ['i1', 'rare', 2]], 1, -50], 'i1'),
('regression magic find scope #1',
[[['i0', 'legendary', 10],
['i1', 'common', 0],
['i2', 'common', 2],
['i3', 'rare', 0],
['i4', 'common', 10]],
5000,
-50],
'i4'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'rare', 50]], 9999, 50], 'i1')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('regression magic find scope #1',
[[['i0', 'legendary', 10],
['i1', 'common', 0],
['i2', 'common', 2],
['i3', 'rare', 0],
['i4', 'common', 10]],
5000,
-50],
'i4'),
('fault site magic find scope #1',
[[['i0', 'common', 10], ['i1', 'common', 5], ['i2', 'legendary', 2], ['i3', 'legendary', 1]], 4998, 181],
'i1'),
('regression magic find scope #2',
[[['i0', 'rare', 5], ['i1', 'rare', 5], ['i2', 'common', 1], ['i3', 'rare', 0], ['i4', 'legendary', 1]],
9999,
-50],
'i2'),
('regression magic find scope #3',
[[['i0', 'common', 10], ['i1', 'common', 1], ['i2', 'legendary', 50], ['i3', 'legendary', 1]], 9999, -50],
'i2'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'rare', 50]], 9999, 50], 'i1')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('regression magic find scope #1',
[[['i0', 'rare', 5], ['i1', 'rare', 5], ['i2', 'common', 1], ['i3', 'rare', 0], ['i4', 'legendary', 1]],
9999,
-50],
'i2'),
('regression magic find scope #2',
[[['i0', 'common', 10], ['i1', 'common', 1], ['i2', 'legendary', 50], ['i3', 'legendary', 1]], 9999, -50],
'i2'),
('regression magic find scope #3',
[[['i0', 'legendary', 10], ['i1', 'rare', 10], ['i2', 'common', 5], ['i3', 'rare', 10], ['i4', 'rare', 1]],
5000,
-66],
'i2'),
('regression magic find scope #4', [[['i0', 'legendary', 1]], 5000, -50], None),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'rare', 50]], 9999, 50], 'i1')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('fault site magic find scope #1',
[[['i0', 'legendary', 41], ['i1', 'rare', 1], ['i2', 'rare', 5], ['i3', 'common', 30]], 5000, 110],
'i0'),
('fault site magic find scope #2',
[[['i0', 'legendary', 55], ['i1', 'common', 50], ['i2', 'legendary', 2], ['i3', 'common', 55]], 5000, 100],
'i0'),
('regression magic find scope #1', [[['i0', 'legendary', 1]], 5000, -50], None),
('regression magic find scope #2',
[[['i0', 'legendary', 1], ['i1', 'common', 1], ['i2', 'legendary', 50]], 1, -50],
'i1'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'common', 50], ['i2', 'legendary', 50]], 793, -50], 'i0')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('fault site magic find scope #1',
[[['i0', 'common', 2], ['i1', 'legendary', 1], ['i2', 'legendary', 2], ['i3', 'legendary', 3]], 3114, 100],
'i2'),
('regression magic find scope #1',
[[['i0', 'legendary', 10], ['i1', 'rare', 10], ['i2', 'common', 5], ['i3', 'rare', 10], ['i4', 'rare', 1]],
5000,
-66],
'i2'),
('partial repair boundary #1',
[[['i0', 'common', 5], ['i1', 'legendary', 2], ['i2', 'rare', 1], ['i3', 'rare', 5], ['i4', 'common', 0]],
5000,
-50],
'i0'),
('regression magic find scope #2',
[[['i0', 'legendary', 1], ['i1', 'rare', 2], ['i2', 'legendary', 5], ['i3', 'rare', 5]], 0, -16],
'i1'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'rare', 1], ['i1', 'common', 10], ['i2', 'legendary', 93]], 0, 100], 'i0')]]
for label, args, expected in cases[N-1]:
check(label, solve(*args), expected)
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 |
|---|---|---|---|
| curse lowers rare #1 | gem | rock | Failed |
| fault site magic find scope #1 | i0 | i0 | Passed |
| fault site magic find scope #2 | i2 | i2 | Passed |
| partial repair boundary #1 | i0 | i1 | Failed |
| regression magic find scope #1 | i2 | i4 | Failed |
| legendary boosted #1 | crown | crown | Passed |
| zero weight entry skipped #1 | c | c | Passed |
| control #1 | i1 | i1 | Passed |
SHA-256 / 997ef8adb5fce8d1705f9d792f565f9a032802b873a42b329d313e2b8cbd5953
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(table, roll, magic_find):
weights = []
for item, rarity, w in table:
if rarity != 'common':
w = w * (100 + magic_find) // 100
weights.append(w)
total = sum(weights)
if total == 0:
return None
target = roll * total // 10000
acc = 0
for (item, rarity, w0), w in zip(table, weights):
acc += w
if target < acc:
return item
return None
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('fault site magic find scope #1',
[[['i0', 'legendary', 10], ['i1', 'rare', 29], ['i2', 'common', 95]], 827, 100],
'i0'),
('fault site magic find scope #2',
[[['i0', 'rare', 2], ['i1', 'common', 10], ['i2', 'legendary', 10], ['i3', 'rare', 10]], 5000, 250],
'i2'),
('partial repair boundary #1', [[['i0', 'rare', 1], ['i1', 'rare', 2]], 1, -50], 'i1'),
('regression magic find scope #1',
[[['i0', 'legendary', 10],
['i1', 'common', 0],
['i2', 'common', 2],
['i3', 'rare', 0],
['i4', 'common', 10]],
5000,
-50],
'i4'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'rare', 50]], 9999, 50], 'i1')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('regression magic find scope #1',
[[['i0', 'legendary', 10],
['i1', 'common', 0],
['i2', 'common', 2],
['i3', 'rare', 0],
['i4', 'common', 10]],
5000,
-50],
'i4'),
('fault site magic find scope #1',
[[['i0', 'common', 10], ['i1', 'common', 5], ['i2', 'legendary', 2], ['i3', 'legendary', 1]], 4998, 181],
'i1'),
('regression magic find scope #2',
[[['i0', 'rare', 5], ['i1', 'rare', 5], ['i2', 'common', 1], ['i3', 'rare', 0], ['i4', 'legendary', 1]],
9999,
-50],
'i2'),
('regression magic find scope #3',
[[['i0', 'common', 10], ['i1', 'common', 1], ['i2', 'legendary', 50], ['i3', 'legendary', 1]], 9999, -50],
'i2'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'rare', 50]], 9999, 50], 'i1')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('regression magic find scope #1',
[[['i0', 'rare', 5], ['i1', 'rare', 5], ['i2', 'common', 1], ['i3', 'rare', 0], ['i4', 'legendary', 1]],
9999,
-50],
'i2'),
('regression magic find scope #2',
[[['i0', 'common', 10], ['i1', 'common', 1], ['i2', 'legendary', 50], ['i3', 'legendary', 1]], 9999, -50],
'i2'),
('regression magic find scope #3',
[[['i0', 'legendary', 10], ['i1', 'rare', 10], ['i2', 'common', 5], ['i3', 'rare', 10], ['i4', 'rare', 1]],
5000,
-66],
'i2'),
('regression magic find scope #4', [[['i0', 'legendary', 1]], 5000, -50], None),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'rare', 50]], 9999, 50], 'i1')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('fault site magic find scope #1',
[[['i0', 'legendary', 41], ['i1', 'rare', 1], ['i2', 'rare', 5], ['i3', 'common', 30]], 5000, 110],
'i0'),
('fault site magic find scope #2',
[[['i0', 'legendary', 55], ['i1', 'common', 50], ['i2', 'legendary', 2], ['i3', 'common', 55]], 5000, 100],
'i0'),
('regression magic find scope #1', [[['i0', 'legendary', 1]], 5000, -50], None),
('regression magic find scope #2',
[[['i0', 'legendary', 1], ['i1', 'common', 1], ['i2', 'legendary', 50]], 1, -50],
'i1'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'common', 10], ['i1', 'common', 50], ['i2', 'legendary', 50]], 793, -50], 'i0')],
[('curse lowers rare #1', [[['gem', 'rare', 10], ['rock', 'common', 10]], 4000, -50], 'rock'),
('fault site magic find scope #1',
[[['i0', 'common', 2], ['i1', 'legendary', 1], ['i2', 'legendary', 2], ['i3', 'legendary', 3]], 3114, 100],
'i2'),
('regression magic find scope #1',
[[['i0', 'legendary', 10], ['i1', 'rare', 10], ['i2', 'common', 5], ['i3', 'rare', 10], ['i4', 'rare', 1]],
5000,
-66],
'i2'),
('partial repair boundary #1',
[[['i0', 'common', 5], ['i1', 'legendary', 2], ['i2', 'rare', 1], ['i3', 'rare', 5], ['i4', 'common', 0]],
5000,
-50],
'i0'),
('regression magic find scope #2',
[[['i0', 'legendary', 1], ['i1', 'rare', 2], ['i2', 'legendary', 5], ['i3', 'rare', 5]], 0, -16],
'i1'),
('legendary boosted #1', [[['sword', 'common', 90], ['crown', 'legendary', 10]], 9500, 100], 'crown'),
('zero weight entry skipped #1',
[[['a', 'common', 1], ['b', 'rare', 0], ['c', 'common', 1]], 5000, 0],
'c'),
('control #1', [[['i0', 'rare', 1], ['i1', 'common', 10], ['i2', 'legendary', 93]], 0, 100], 'i0')]]
for label, args, expected in cases[N-1]:
check(label, solve(*args), expected)
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 |
|---|---|---|---|
| curse lowers rare #1 | rock | rock | Passed |
| fault site magic find scope #1 | i0 | i0 | Passed |
| fault site magic find scope #2 | i2 | i2 | Passed |
| partial repair boundary #1 | i1 | i1 | Passed |
| regression magic find scope #1 | i4 | i4 | Passed |
| legendary boosted #1 | crown | crown | Passed |
| zero weight entry skipped #1 | c | c | Passed |
| control #1 | i1 | i1 | Passed |
SHA-256 / 30e6506a00c7b30b54d2ff8788185ce2ef25ccfc00c532d9ba421d9bded64ec5
Verification & scope
Deterministic toy contract stipulated for this model; integer or exact arithmetic only, not a reproduction of any specific game engine. 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 2026-09-29T14:50:46.628644+00:00.
Case digest / 5b3a05e3e3eb4c81c1f18e5ba41e48d92868cd62ec61b69d6edc2dfc0952663c