FA-21656 / Assistive announcements / Open access

Ready producer continues buffering announcements · case 01

The announcement trace violates the stated producer-readiness contract.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Fault site: elif state=='ready': out.append(e[1]) is implemented as elif state=='ready': pending.append(e[1])

VERIFIED REPAIR

Restore the stated transition: elif state=='ready': out.append(e[1])

Unsuccessful approach: The attempted repair substitutes elif state=='ready': out.append(e[1][:1]) and still violates a regression oracle.

Case contract

Announcement producer has booting/ready/failed state and generation. Start increments generation, enters booting, clears deferred messages. Publish during booting queues; ready publishes directly; failed drops. Ready callback must match generation, drains queued messages FIFO, and is ignored after failure. Fail matching generation clears deferred and announces unavailable once. Retry is a start. Stop fails silently and advances generation. Report speech,state,generation,deferred.

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):
    state='failed'; generation=0; pending=[]; out=[]
    for e in events:
        if e[0] in ('start','retry'):
            generation+=1; state='booting'; pending=[]
        elif e[0]=='stop': state='failed'; generation+=1; pending=[]
        elif e[0]=='publish':
            if state=='booting': pending.append(e[1])
            elif state=='ready': pending.append(e[1])
        elif e[0] in ('ready','fail'):
            if e[1]!=generation: continue
            if state!='booting': continue
            if e[0]=='ready':
                state='ready'
                out.extend(pending)
                pending.clear()
            else:
                state='failed'; pending.clear(); out.append('unavailable')
    return [out,state,generation,pending]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['start'],['publish','first'*N],['publish','second'],['ready',1],['publish','third']]", "[['start'],['publish','old'],['retry'],['publish','new'*N],['ready',1]]", "[['start'],['publish','deferred'*N],['fail',1],['ready',1],['publish','should-drop']]", "[['start'],['publish','deferred'*N],['stop'],['ready',1]]", "[['start'],['fail',1],['fail',1],['retry'],['publish','retry'*N],['ready',2]]", "[['publish','dropped'*N],['ready',0]]", '[]']
expected = {1: [[['first', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['new']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 2: [[['firstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 3: [[['firstfirstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnewnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 4: [[['firstfirstfirstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnewnewnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretryretryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 5: [[['firstfirstfirstfirstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnewnewnewnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretryretryretryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 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 fixture	Actual	Expected	Outcome
trace-1	`[['first', 'second'], 'ready', 1, ['third']]`	`[['first', 'second', 'third'], 'ready', 1, []]`	Failed
trace-2	`[[], 'booting', 2, ['new']]`	`[[], 'booting', 2, ['new']]`	Passed
trace-3	`[['unavailable'], 'failed', 1, []]`	`[['unavailable'], 'failed', 1, []]`	Passed
trace-4	`[[], 'failed', 2, []]`	`[[], 'failed', 2, []]`	Passed
trace-5	`[['unavailable', 'retry'], 'ready', 2, []]`	`[['unavailable', 'retry'], 'ready', 2, []]`	Passed
trace-6	`[[], 'failed', 0, []]`	`[[], 'failed', 0, []]`	Passed
trace-7	`[[], 'failed', 0, []]`	`[[], 'failed', 0, []]`	Passed

SHA-256 / 97d0ca98fe723cf2f989a0794e64257664590bfeb1383a5d128bdeef099b22d1

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(events):
    state='failed'; generation=0; pending=[]; out=[]
    for e in events:
        if e[0] in ('start','retry'):
            generation+=1; state='booting'; pending=[]
        elif e[0]=='stop': state='failed'; generation+=1; pending=[]
        elif e[0]=='publish':
            if state=='booting': pending.append(e[1])
            elif state=='ready': out.append(e[1][:1])
        elif e[0] in ('ready','fail'):
            if e[1]!=generation: continue
            if state!='booting': continue
            if e[0]=='ready':
                state='ready'
                out.extend(pending)
                pending.clear()
            else:
                state='failed'; pending.clear(); out.append('unavailable')
    return [out,state,generation,pending]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['start'],['publish','first'*N],['publish','second'],['ready',1],['publish','third']]", "[['start'],['publish','old'],['retry'],['publish','new'*N],['ready',1]]", "[['start'],['publish','deferred'*N],['fail',1],['ready',1],['publish','should-drop']]", "[['start'],['publish','deferred'*N],['stop'],['ready',1]]", "[['start'],['fail',1],['fail',1],['retry'],['publish','retry'*N],['ready',2]]", "[['publish','dropped'*N],['ready',0]]", '[]']
expected = {1: [[['first', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['new']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 2: [[['firstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 3: [[['firstfirstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnewnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 4: [[['firstfirstfirstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnewnewnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretryretryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 5: [[['firstfirstfirstfirstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnewnewnewnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretryretryretryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 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 fixture	Actual	Expected	Outcome
trace-1	`[['first', 'second', 't'], 'ready', 1, []]`	`[['first', 'second', 'third'], 'ready', 1, []]`	Failed
trace-2	`[[], 'booting', 2, ['new']]`	`[[], 'booting', 2, ['new']]`	Passed
trace-3	`[['unavailable'], 'failed', 1, []]`	`[['unavailable'], 'failed', 1, []]`	Passed
trace-4	`[[], 'failed', 2, []]`	`[[], 'failed', 2, []]`	Passed
trace-5	`[['unavailable', 'retry'], 'ready', 2, []]`	`[['unavailable', 'retry'], 'ready', 2, []]`	Passed
trace-6	`[[], 'failed', 0, []]`	`[[], 'failed', 0, []]`	Passed
trace-7	`[[], 'failed', 0, []]`	`[[], 'failed', 0, []]`	Passed

SHA-256 / 37421aaa3042cfb7e042adde64b8b6c720742315d653dcab75d619abc5e8ffd5

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(events):
    state='failed'; generation=0; pending=[]; out=[]
    for e in events:
        if e[0] in ('start','retry'):
            generation+=1; state='booting'; pending=[]
        elif e[0]=='stop': state='failed'; generation+=1; pending=[]
        elif e[0]=='publish':
            if state=='booting': pending.append(e[1])
            elif state=='ready': out.append(e[1])
        elif e[0] in ('ready','fail'):
            if e[1]!=generation: continue
            if state!='booting': continue
            if e[0]=='ready':
                state='ready'
                out.extend(pending)
                pending.clear()
            else:
                state='failed'; pending.clear(); out.append('unavailable')
    return [out,state,generation,pending]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['start'],['publish','first'*N],['publish','second'],['ready',1],['publish','third']]", "[['start'],['publish','old'],['retry'],['publish','new'*N],['ready',1]]", "[['start'],['publish','deferred'*N],['fail',1],['ready',1],['publish','should-drop']]", "[['start'],['publish','deferred'*N],['stop'],['ready',1]]", "[['start'],['fail',1],['fail',1],['retry'],['publish','retry'*N],['ready',2]]", "[['publish','dropped'*N],['ready',0]]", '[]']
expected = {1: [[['first', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['new']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 2: [[['firstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 3: [[['firstfirstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnewnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 4: [[['firstfirstfirstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnewnewnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretryretryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 0, []]], 5: [[['firstfirstfirstfirstfirst', 'second', 'third'], 'ready', 1, []], [[], 'booting', 2, ['newnewnewnewnew']], [['unavailable'], 'failed', 1, []], [[], 'failed', 2, []], [['unavailable', 'retryretryretryretryretry'], 'ready', 2, []], [[], 'failed', 0, []], [[], 'failed', 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 fixture	Actual	Expected	Outcome
trace-1	`[['first', 'second', 'third'], 'ready', 1, []]`	`[['first', 'second', 'third'], 'ready', 1, []]`	Passed
trace-2	`[[], 'booting', 2, ['new']]`	`[[], 'booting', 2, ['new']]`	Passed
trace-3	`[['unavailable'], 'failed', 1, []]`	`[['unavailable'], 'failed', 1, []]`	Passed
trace-4	`[[], 'failed', 2, []]`	`[[], 'failed', 2, []]`	Passed
trace-5	`[['unavailable', 'retry'], 'ready', 2, []]`	`[['unavailable', 'retry'], 'ready', 2, []]`	Passed
trace-6	`[[], 'failed', 0, []]`	`[[], 'failed', 0, []]`	Passed
trace-7	`[[], 'failed', 0, []]`	`[[], 'failed', 0, []]`	Passed

SHA-256 / f52c75e4328c7260e45f1f37a25998915ef45e21adbd89a998ab5a99263e9daa

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 2026-09-29T14:40:30.925279+00:00.

Case digest / d0fd36ebd09f9f81cccf51ed9359c0ebcd88da9a2f8b3dc91cec00e17661d6c3