FAILURE MAP
← Case archive

FA-21156 / Assistive announcements / Open access

Released topic summaries reverse their first-seen order · case 01

The announcement trace violates the stated quiet-session contract.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Fault site: out.extend([[k,v[0],v[1]] for k,v in pending.items()]) is implemented as out.extend([[k,v[0],v[1]] for k,v in reversed(list(pending.items()))])

THE FAILURE

Fault site: out.extend([[k,v[0],v[1]] for k,v in pending.items()]) is implemented as out.extend([[k,v[0],v[1]] for k,v in reversed(list(pending.items()))])

Unsuccessful approach: The attempted repair substitutes out.extend([[k,v[0],1] for k,v in pending.items()]) and still violates a regression oracle.

Case contract

Quiet nesting is a counter. Enter increments; leave decrements without going negative. Ordinary messages during quiet replace a per-topic summary [latest,count], emergency speech always emits immediately. Final leave emits summaries in topic first-seen order as [topic,latest,count]. Remove-topic discards only that summary. Reset quiet silently discards backlog. Ordinary speech outside quiet emits directly with count1. Report output, nesting and pending summaries.

Why this case matters

Deterministic controlled model of assistive announcement delivery.

1 / The failure

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

N = 1
observations = []
def solve(events):
    depth=0; pending={}; out=[]
    for e in events:
        if e[0]=='enter': depth+=1
        elif e[0]=='leave':
            was=depth; depth=max(0,depth-1)
            if was>0 and depth==0:
                out.extend([[k,v[0],v[1]] for k,v in reversed(list(pending.items()))])
                pending.clear()
        elif e[0]=='reset': depth=0; pending.clear()
        elif e[0]=='remove': pending.pop(e[1],None)
        elif e[0]=='message':
            if e[3]=='emergency': out.append([e[1],e[2],1])
            elif depth:
                old=pending.get(e[1],['',0])
                pending[e[1]]=[e[2],old[1]+1]
            else: out.append([e[1],e[2],1])
    return [out,depth,[[k]+v for k,v in pending.items()]]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['enter'],['enter'],['message','a','first'*N,'normal'],['leave']]", "[['enter'],['message','z','old','normal'],['message','a','a'*N,'normal'],['message','z','new','normal'],['leave'],['enter'],['leave']]", "[['enter'],['message','a','urgent'*N,'emergency']]", "[['enter'],['message','a','urgent'*N,'emergency'],['message','b','deferred','normal'],['leave']]", "[['enter'],['message','a','a'*N,'normal'],['message','b','b','normal'],['remove','a']]", "[['enter'],['message','a','x'*N,'normal'],['reset']]", "[['message','a','direct'*N,'normal'],['leave'],['leave']]", "[['enter'],['message','a','x'*N,'normal'],['leave'],['leave']]"]
expected = {1: [[[], 1, [['a', 'first', 1]]], [[['z', 'new', 2], ['a', 'a', 1]], 0, []], [[['a', 'urgent', 1]], 1, []], [[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'direct', 1]], 0, []], [[['a', 'x', 1]], 0, []]], 2: [[[], 1, [['a', 'firstfirst', 1]]], [[['z', 'new', 2], ['a', 'aa', 1]], 0, []], [[['a', 'urgenturgent', 1]], 1, []], [[['a', 'urgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirect', 1]], 0, []], [[['a', 'xx', 1]], 0, []]], 3: [[[], 1, [['a', 'firstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaa', 1]], 0, []], [[['a', 'urgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirect', 1]], 0, []], [[['a', 'xxx', 1]], 0, []]], 4: [[[], 1, [['a', 'firstfirstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaaa', 1]], 0, []], [[['a', 'urgenturgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirectdirect', 1]], 0, []], [[['a', 'xxxx', 1]], 0, []]], 5: [[[], 1, [['a', 'firstfirstfirstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaaaa', 1]], 0, []], [[['a', 'urgenturgenturgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirectdirectdirect', 1]], 0, []], [[['a', 'xxxxx', 1]], 0, []]]}[N]
for i, expression in enumerate(fixtures):
    check("trace-"+str(i+1), solve(eval(expression)), expected[i])
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
trace-1[[], 1, [['a', 'first', 1]]][[], 1, [['a', 'first', 1]]]Passed
trace-2[[['a', 'a', 1], ['z', 'new', 2]], 0, []][[['z', 'new', 2], ['a', 'a', 1]], 0, []]Failed
trace-3[[['a', 'urgent', 1]], 1, []][[['a', 'urgent', 1]], 1, []]Passed
trace-4[[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []][[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []]Passed
trace-5[[], 1, [['b', 'b', 1]]][[], 1, [['b', 'b', 1]]]Passed
trace-6[[], 0, []][[], 0, []]Passed
trace-7[[['a', 'direct', 1]], 0, []][[['a', 'direct', 1]], 0, []]Passed
trace-8[[['a', 'x', 1]], 0, []][[['a', 'x', 1]], 0, []]Passed

SHA-256 / 302d49bd642b4477cbad8594ebffa3d42c1447803238328e1ebee830bbb391b1

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(events):
    depth=0; pending={}; out=[]
    for e in events:
        if e[0]=='enter': depth+=1
        elif e[0]=='leave':
            was=depth; depth=max(0,depth-1)
            if was>0 and depth==0:
                out.extend([[k,v[0],1] for k,v in pending.items()])
                pending.clear()
        elif e[0]=='reset': depth=0; pending.clear()
        elif e[0]=='remove': pending.pop(e[1],None)
        elif e[0]=='message':
            if e[3]=='emergency': out.append([e[1],e[2],1])
            elif depth:
                old=pending.get(e[1],['',0])
                pending[e[1]]=[e[2],old[1]+1]
            else: out.append([e[1],e[2],1])
    return [out,depth,[[k]+v for k,v in pending.items()]]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['enter'],['enter'],['message','a','first'*N,'normal'],['leave']]", "[['enter'],['message','z','old','normal'],['message','a','a'*N,'normal'],['message','z','new','normal'],['leave'],['enter'],['leave']]", "[['enter'],['message','a','urgent'*N,'emergency']]", "[['enter'],['message','a','urgent'*N,'emergency'],['message','b','deferred','normal'],['leave']]", "[['enter'],['message','a','a'*N,'normal'],['message','b','b','normal'],['remove','a']]", "[['enter'],['message','a','x'*N,'normal'],['reset']]", "[['message','a','direct'*N,'normal'],['leave'],['leave']]", "[['enter'],['message','a','x'*N,'normal'],['leave'],['leave']]"]
expected = {1: [[[], 1, [['a', 'first', 1]]], [[['z', 'new', 2], ['a', 'a', 1]], 0, []], [[['a', 'urgent', 1]], 1, []], [[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'direct', 1]], 0, []], [[['a', 'x', 1]], 0, []]], 2: [[[], 1, [['a', 'firstfirst', 1]]], [[['z', 'new', 2], ['a', 'aa', 1]], 0, []], [[['a', 'urgenturgent', 1]], 1, []], [[['a', 'urgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirect', 1]], 0, []], [[['a', 'xx', 1]], 0, []]], 3: [[[], 1, [['a', 'firstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaa', 1]], 0, []], [[['a', 'urgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirect', 1]], 0, []], [[['a', 'xxx', 1]], 0, []]], 4: [[[], 1, [['a', 'firstfirstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaaa', 1]], 0, []], [[['a', 'urgenturgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirectdirect', 1]], 0, []], [[['a', 'xxxx', 1]], 0, []]], 5: [[[], 1, [['a', 'firstfirstfirstfirstfirst', 1]]], [[['z', 'new', 2], ['a', 'aaaaa', 1]], 0, []], [[['a', 'urgenturgenturgenturgenturgent', 1]], 1, []], [[['a', 'urgenturgenturgenturgenturgent', 1], ['b', 'deferred', 1]], 0, []], [[], 1, [['b', 'b', 1]]], [[], 0, []], [[['a', 'directdirectdirectdirectdirect', 1]], 0, []], [[['a', 'xxxxx', 1]], 0, []]]}[N]
for i, expression in enumerate(fixtures):
    check("trace-"+str(i+1), solve(eval(expression)), expected[i])
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
trace-1[[], 1, [['a', 'first', 1]]][[], 1, [['a', 'first', 1]]]Passed
trace-2[[['z', 'new', 1], ['a', 'a', 1]], 0, []][[['z', 'new', 2], ['a', 'a', 1]], 0, []]Failed
trace-3[[['a', 'urgent', 1]], 1, []][[['a', 'urgent', 1]], 1, []]Passed
trace-4[[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []][[['a', 'urgent', 1], ['b', 'deferred', 1]], 0, []]Passed
trace-5[[], 1, [['b', 'b', 1]]][[], 1, [['b', 'b', 1]]]Passed
trace-6[[], 0, []][[], 0, []]Passed
trace-7[[['a', 'direct', 1]], 0, []][[['a', 'direct', 1]], 0, []]Passed
trace-8[[['a', 'x', 1]], 0, []][[['a', 'x', 1]], 0, []]Passed

SHA-256 / 9b934648f618f42454b6259fb25eaf81054d82e81fc24eef693934b2282195a0

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 8 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

Stipulated bounded policy, not a browser, speech engine, platform API, or standards conformance claim. 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 2026-09-29T14:40:26.182140+00:00.

Case digest / e614a112976ec3bb76c35b8877aa558a23e72a020f0f9db92845dbf9db8a3c99