FAILURE MAP
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FA-20361 / Assistive announcements / Open access

An obsolete receipt acknowledges replacement speech · case 01

The announcement trace violates the stated delivery-receipts contract.

Verified by executionVariant 1 · 10 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Fault site: if pending[ident][1] != ticket: continue is implemented as if pending[ident][1] < ticket: continue

THE FAILURE

Fault site: if pending[ident][1] != ticket: continue is implemented as if pending[ident][1] < ticket: continue

Unsuccessful approach: The attempted repair substitutes if pending[ident][1] > ticket + 1: continue and still violates a regression oracle.

Case contract

A delivery is keyed by (utterance, generation). Submit replaces pending text for that key. A receipt is accepted only for the active generation and exact serial; accepted receipts append spoken text, remove pending, and retire the serial. Disconnect discards pending, increments generation, resets serial. Duplicate receipts do nothing. Report spoken, pending count, generation and next serial.

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):
    pending = {}; retired = set(); spoken = []; generation = 0; serial = 0
    for e in events:
        if e[0] == 'submit':
            serial += 1
            pending[e[1]] = [generation, serial, e[2]]
        elif e[0] == 'receipt':
            ident, epoch, ticket = e[1:]
            if epoch != generation: continue
            if ticket in retired: continue
            if ident not in pending: continue
            if pending[ident][1] < ticket: continue
            spoken.append(pending[ident][2])
            del pending[ident]
            retired.add(ticket)
        elif e[0] == 'disconnect':
            pending.clear()
            generation += 1
            serial = 0
            retired.clear()
    return [spoken, len(pending), generation, serial]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['submit','a','word'*N],['submit','b','other'],['receipt','a',0,1],['receipt','b',0,1],['receipt','b',0,2]]", "[['submit','a','old'],['submit','a','new'*N],['receipt','a',0,1],['receipt','a',0,2]]", "[['submit','a','old'],['submit','b','stale'],['disconnect'],['submit','a','new'*N],['receipt','a',0,1],['receipt','a',1,1]]", "[['disconnect'],['disconnect'],['submit','a','x'*N],['receipt','a',2,1]]", "[['submit','a','hello'*N],['receipt','a',0,1],['receipt','a',0,1]]", "[['submit','a','hi'*N],['submit','b','bye'],['receipt','a',0,1],['receipt','b',0,2],['disconnect'],['submit','a','new'],['receipt','a',1,1]]", "[['disconnect'],['submit','a','fresh'*N],['receipt','a',0,1]]", "[['submit','a','old'],['submit','b','old'],['disconnect']]", "[['submit','a','old'],['submit','a','new'*N],['receipt','a',0,1]]", '[]']
expected = {1: [[['word', 'other'], 0, 0, 2], [['new'], 0, 0, 2], [['new'], 0, 1, 1], [['x'], 0, 2, 1], [['hello'], 0, 0, 1], [['hi', 'bye', 'new'], 0, 1, 1], [[], 1, 1, 1], [[], 0, 1, 0], [[], 1, 0, 2], [[], 0, 0, 0]], 2: [[['wordword', 'other'], 0, 0, 2], [['newnew'], 0, 0, 2], [['newnew'], 0, 1, 1], [['xx'], 0, 2, 1], [['hellohello'], 0, 0, 1], [['hihi', 'bye', 'new'], 0, 1, 1], [[], 1, 1, 1], [[], 0, 1, 0], [[], 1, 0, 2], [[], 0, 0, 0]], 3: [[['wordwordword', 'other'], 0, 0, 2], [['newnewnew'], 0, 0, 2], [['newnewnew'], 0, 1, 1], [['xxx'], 0, 2, 1], [['hellohellohello'], 0, 0, 1], [['hihihi', 'bye', 'new'], 0, 1, 1], [[], 1, 1, 1], [[], 0, 1, 0], [[], 1, 0, 2], [[], 0, 0, 0]], 4: [[['wordwordwordword', 'other'], 0, 0, 2], [['newnewnewnew'], 0, 0, 2], [['newnewnewnew'], 0, 1, 1], [['xxxx'], 0, 2, 1], [['hellohellohellohello'], 0, 0, 1], [['hihihihi', 'bye', 'new'], 0, 1, 1], [[], 1, 1, 1], [[], 0, 1, 0], [[], 1, 0, 2], [[], 0, 0, 0]], 5: [[['wordwordwordwordword', 'other'], 0, 0, 2], [['newnewnewnewnew'], 0, 0, 2], [['newnewnewnewnew'], 0, 1, 1], [['xxxxx'], 0, 2, 1], [['hellohellohellohellohello'], 0, 0, 1], [['hihihihihi', 'bye', 'new'], 0, 1, 1], [[], 1, 1, 1], [[], 0, 1, 0], [[], 1, 0, 2], [[], 0, 0, 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[['word', 'other'], 0, 0, 2][['word', 'other'], 0, 0, 2]Passed
trace-2[['new'], 0, 0, 2][['new'], 0, 0, 2]Passed
trace-3[['new'], 0, 1, 1][['new'], 0, 1, 1]Passed
trace-4[['x'], 0, 2, 1][['x'], 0, 2, 1]Passed
trace-5[['hello'], 0, 0, 1][['hello'], 0, 0, 1]Passed
trace-6[['hi', 'bye', 'new'], 0, 1, 1][['hi', 'bye', 'new'], 0, 1, 1]Passed
trace-7[[], 1, 1, 1][[], 1, 1, 1]Passed
trace-8[[], 0, 1, 0][[], 0, 1, 0]Passed
trace-9[['new'], 0, 0, 2][[], 1, 0, 2]Failed
trace-10[[], 0, 0, 0][[], 0, 0, 0]Passed

SHA-256 / 81a045e3cfae9bbbe92304de1a5f8e560203e91b31446ff48766e68c10cdf9d9

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(events):
    pending = {}; retired = set(); spoken = []; generation = 0; serial = 0
    for e in events:
        if e[0] == 'submit':
            serial += 1
            pending[e[1]] = [generation, serial, e[2]]
        elif e[0] == 'receipt':
            ident, epoch, ticket = e[1:]
            if epoch != generation: continue
            if ticket in retired: continue
            if ident not in pending: continue
            if pending[ident][1] > ticket + 1: continue
            spoken.append(pending[ident][2])
            del pending[ident]
            retired.add(ticket)
        elif e[0] == 'disconnect':
            pending.clear()
            generation += 1
            serial = 0
            retired.clear()
    return [spoken, len(pending), generation, serial]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['submit','a','word'*N],['submit','b','other'],['receipt','a',0,1],['receipt','b',0,1],['receipt','b',0,2]]", "[['submit','a','old'],['submit','a','new'*N],['receipt','a',0,1],['receipt','a',0,2]]", "[['submit','a','old'],['submit','b','stale'],['disconnect'],['submit','a','new'*N],['receipt','a',0,1],['receipt','a',1,1]]", "[['disconnect'],['disconnect'],['submit','a','x'*N],['receipt','a',2,1]]", "[['submit','a','hello'*N],['receipt','a',0,1],['receipt','a',0,1]]", "[['submit','a','hi'*N],['submit','b','bye'],['receipt','a',0,1],['receipt','b',0,2],['disconnect'],['submit','a','new'],['receipt','a',1,1]]", "[['disconnect'],['submit','a','fresh'*N],['receipt','a',0,1]]", "[['submit','a','old'],['submit','b','old'],['disconnect']]", "[['submit','a','old'],['submit','a','new'*N],['receipt','a',0,1]]", '[]']
expected = {1: [[['word', 'other'], 0, 0, 2], [['new'], 0, 0, 2], [['new'], 0, 1, 1], [['x'], 0, 2, 1], [['hello'], 0, 0, 1], [['hi', 'bye', 'new'], 0, 1, 1], [[], 1, 1, 1], [[], 0, 1, 0], [[], 1, 0, 2], [[], 0, 0, 0]], 2: [[['wordword', 'other'], 0, 0, 2], [['newnew'], 0, 0, 2], [['newnew'], 0, 1, 1], [['xx'], 0, 2, 1], [['hellohello'], 0, 0, 1], [['hihi', 'bye', 'new'], 0, 1, 1], [[], 1, 1, 1], [[], 0, 1, 0], [[], 1, 0, 2], [[], 0, 0, 0]], 3: [[['wordwordword', 'other'], 0, 0, 2], [['newnewnew'], 0, 0, 2], [['newnewnew'], 0, 1, 1], [['xxx'], 0, 2, 1], [['hellohellohello'], 0, 0, 1], [['hihihi', 'bye', 'new'], 0, 1, 1], [[], 1, 1, 1], [[], 0, 1, 0], [[], 1, 0, 2], [[], 0, 0, 0]], 4: [[['wordwordwordword', 'other'], 0, 0, 2], [['newnewnewnew'], 0, 0, 2], [['newnewnewnew'], 0, 1, 1], [['xxxx'], 0, 2, 1], [['hellohellohellohello'], 0, 0, 1], [['hihihihi', 'bye', 'new'], 0, 1, 1], [[], 1, 1, 1], [[], 0, 1, 0], [[], 1, 0, 2], [[], 0, 0, 0]], 5: [[['wordwordwordwordword', 'other'], 0, 0, 2], [['newnewnewnewnew'], 0, 0, 2], [['newnewnewnewnew'], 0, 1, 1], [['xxxxx'], 0, 2, 1], [['hellohellohellohellohello'], 0, 0, 1], [['hihihihihi', 'bye', 'new'], 0, 1, 1], [[], 1, 1, 1], [[], 0, 1, 0], [[], 1, 0, 2], [[], 0, 0, 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[['word', 'other'], 0, 0, 2][['word', 'other'], 0, 0, 2]Passed
trace-2[['new'], 0, 0, 2][['new'], 0, 0, 2]Passed
trace-3[['new'], 0, 1, 1][['new'], 0, 1, 1]Passed
trace-4[['x'], 0, 2, 1][['x'], 0, 2, 1]Passed
trace-5[['hello'], 0, 0, 1][['hello'], 0, 0, 1]Passed
trace-6[['hi', 'bye', 'new'], 0, 1, 1][['hi', 'bye', 'new'], 0, 1, 1]Passed
trace-7[[], 1, 1, 1][[], 1, 1, 1]Passed
trace-8[[], 0, 1, 0][[], 0, 1, 0]Passed
trace-9[['new'], 0, 0, 2][[], 1, 0, 2]Failed
trace-10[[], 0, 0, 0][[], 0, 0, 0]Passed

SHA-256 / 6d67f4215e09de395a1b4a473023c405dced7becf68758a2f2a56657da810cbb

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 10 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.

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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 2026-09-29T14:40:18.539254+00:00.

Case digest / 3d3799e05939a436ff65072058e0bad89a0494bd3a79ca343e596058d513a868