FAILURE MAP
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FA-26516 / HTTP ranges / Open access

Assembly expires with its earliest expiring fragment · case 01

Assembly expires with its earliest expiring fragment.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The cache-expiry-minimum decision uses return max(0,max(expiries,default=now)-now).

VERIFIED REPAIR

Apply the bounded decision exactly: return max(0,min(expiries)-now) if expiries else 0

Unsuccessful approach: The partial repair uses return max(0,sum(expiries)//len(expiries)-now) if expiries else 0, which still violates the stated contract.

Case contract

Return remaining freshness min(expiries)-now clipped at zero, or zero when no fragments contribute.

Why this case matters

Range responses combine representation identity, conditional requests, framing, and partial-object state.

1 / The failure

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

N = 1
observations = []
def solve(expiries, now):
    return max(0,max(expiries,default=now)-now)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('cache-expiry-minimum fixture 0', solve([N,3*N],0), N)
check('cache-expiry-minimum fixture 1', solve([N,3*N],2*N), 0)
check('cache-expiry-minimum fixture 2', solve([],N), 0)
check('cache-expiry-minimum fixture 3', solve([N],0), N)
check('cache-expiry-minimum fixture 4', solve([N,N],N), 0)
check('cache-expiry-minimum fixture 5', solve([2*N,4*N],N), N)
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
cache-expiry-minimum fixture 031Failed
cache-expiry-minimum fixture 110Failed
cache-expiry-minimum fixture 200Passed
cache-expiry-minimum fixture 311Passed
cache-expiry-minimum fixture 400Passed
cache-expiry-minimum fixture 531Failed

SHA-256 / efab4f28dccc0318c0a7dc4ee11e7e6c2be6186b7912255ec8ae6c340a729345

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(expiries, now):
    return max(0,sum(expiries)//len(expiries)-now) if expiries else 0
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('cache-expiry-minimum fixture 0', solve([N,3*N],0), N)
check('cache-expiry-minimum fixture 1', solve([N,3*N],2*N), 0)
check('cache-expiry-minimum fixture 2', solve([],N), 0)
check('cache-expiry-minimum fixture 3', solve([N],0), N)
check('cache-expiry-minimum fixture 4', solve([N,N],N), 0)
check('cache-expiry-minimum fixture 5', solve([2*N,4*N],N), N)
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
cache-expiry-minimum fixture 021Failed
cache-expiry-minimum fixture 100Passed
cache-expiry-minimum fixture 200Passed
cache-expiry-minimum fixture 311Passed
cache-expiry-minimum fixture 400Passed
cache-expiry-minimum fixture 521Failed

SHA-256 / 2ecc4a45ea2a8ea805d1713475b3ba4e8faf450f7d5f4a27b625e67875f89802

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(expiries, now):
    return max(0,min(expiries)-now) if expiries else 0
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('cache-expiry-minimum fixture 0', solve([N,3*N],0), N)
check('cache-expiry-minimum fixture 1', solve([N,3*N],2*N), 0)
check('cache-expiry-minimum fixture 2', solve([],N), 0)
check('cache-expiry-minimum fixture 3', solve([N],0), N)
check('cache-expiry-minimum fixture 4', solve([N,N],N), 0)
check('cache-expiry-minimum fixture 5', solve([2*N,4*N],N), N)
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
cache-expiry-minimum fixture 011Passed
cache-expiry-minimum fixture 100Passed
cache-expiry-minimum fixture 200Passed
cache-expiry-minimum fixture 311Passed
cache-expiry-minimum fixture 400Passed
cache-expiry-minimum fixture 511Passed

SHA-256 / b540465634b347b1835810ff9069d1c69b55a26f904378d07837e4d18daba699

Verification & scope

Deterministic simplified range service, with stipulated local policies and already parsed trusted inputs; not a complete HTTP implementation. 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 2026-09-29T14:41:16.728140+00:00.

Case digest / 259f86ee2de09705db5c5010474caafccca36991cbcf75dc750e5179ae4f6160