FA-20726 / Assistive announcements / Open access

Queued speech drops the selected voice · case 01

The announcement trace violates the stated locale-snapshot contract.

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

ROOT CAUSE

Fault site: q.append([lang,voice,rendered]) is implemented as q.append([lang,'default',rendered])

VERIFIED REPAIR

Restore the stated transition: q.append([lang,voice,rendered])

Unsuccessful approach: The attempted repair substitutes q.append(['en',voice,rendered]) and still violates a regression oracle.

Case contract

Configure a current language, voice, and pronunciation dictionary. Queue captures text rendered with whole whitespace-delimited token substitutions plus current language and voice. Dictionary edits affect future queues only. Remove deletes one pronunciation. Voice reset restores default without changing language. Flush speaks queued envelopes FIFO. Language switch clears dictionary. Report spoken and queued envelopes.

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):
    lang='en'; voice='default'; words={}; q=[]; spoken=[]
    for e in events:
        if e[0]=='language': lang=e[1]; words.clear()
        elif e[0]=='voice': voice=e[1]
        elif e[0]=='define': words[e[1]]=e[2]
        elif e[0]=='remove': words.pop(e[1],None)
        elif e[0]=='reset-voice': voice='default'
        elif e[0]=='queue':
            tokens=e[1].split(' ')
            rendered=' '.join(words.get(token,token) for token in tokens)
            q.append([lang,'default',rendered])
        elif e[0]=='flush':
            spoken.extend(q)
            q.clear()
    return [spoken,q,lang,voice,sorted(words.items())]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['language','fr'],['voice','alto'],['define','AI','A I'],['queue','AI '*N],['voice','bass'],['queue','AI'],['flush'],['flush']]", "[['define','a','first'],['define','a','second'],['queue','a '*N],['flush']]", "[['define','A','upper'],['define','a','lower'],['queue','A a Aa '*N],['remove','A'],['queue','A a'],['flush']]", "[['define','a','one'],['define','b','two'],['language','de'],['queue','a b '*N],['flush']]", "[['language','fr'],['define','a','ah'],['voice','alto'],['reset-voice'],['queue','a '*N],['flush']]", "[['queue','  x  '*N],['flush']]", '[]']
expected = {1: [[[['fr', 'alto', 'A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 2: [[[['fr', 'alto', 'A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 3: [[[['fr', 'alto', 'A I A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 4: [[[['fr', 'alto', 'A I A I A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x    x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 5: [[[['fr', 'alto', 'A I A I A I A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second second second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa upper lower Aa upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b a b a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ah ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x    x    x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]]}[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	`[[['fr', 'default', 'A I '], ['fr', 'default', 'A I']], [], 'fr', 'bass', [['AI', 'A I']]]`	`[[['fr', 'alto', 'A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [['AI', 'A I']]]`	Failed
trace-2	`[[['en', 'default', 'second ']], [], 'en', 'default', [['a', 'second']]]`	`[[['en', 'default', 'second ']], [], 'en', 'default', [['a', 'second']]]`	Passed
trace-3	`[[['en', 'default', 'upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [['a', 'lower']]]`	`[[['en', 'default', 'upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [['a', 'lower']]]`	Passed
trace-4	`[[['de', 'default', 'a b ']], [], 'de', 'default', []]`	`[[['de', 'default', 'a b ']], [], 'de', 'default', []]`	Passed
trace-5	`[[['fr', 'default', 'ah ']], [], 'fr', 'default', [['a', 'ah']]]`	`[[['fr', 'default', 'ah ']], [], 'fr', 'default', [['a', 'ah']]]`	Passed
trace-6	`[[['en', 'default', ' x ']], [], 'en', 'default', []]`	`[[['en', 'default', ' x ']], [], 'en', 'default', []]`	Passed
trace-7	`[[], [], 'en', 'default', []]`	`[[], [], 'en', 'default', []]`	Passed

SHA-256 / 66743372b7d8e54f82df3fb8f09aca19f18fe22ba7806e3df6281951eb09fb97

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(events):
    lang='en'; voice='default'; words={}; q=[]; spoken=[]
    for e in events:
        if e[0]=='language': lang=e[1]; words.clear()
        elif e[0]=='voice': voice=e[1]
        elif e[0]=='define': words[e[1]]=e[2]
        elif e[0]=='remove': words.pop(e[1],None)
        elif e[0]=='reset-voice': voice='default'
        elif e[0]=='queue':
            tokens=e[1].split(' ')
            rendered=' '.join(words.get(token,token) for token in tokens)
            q.append(['en',voice,rendered])
        elif e[0]=='flush':
            spoken.extend(q)
            q.clear()
    return [spoken,q,lang,voice,sorted(words.items())]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['language','fr'],['voice','alto'],['define','AI','A I'],['queue','AI '*N],['voice','bass'],['queue','AI'],['flush'],['flush']]", "[['define','a','first'],['define','a','second'],['queue','a '*N],['flush']]", "[['define','A','upper'],['define','a','lower'],['queue','A a Aa '*N],['remove','A'],['queue','A a'],['flush']]", "[['define','a','one'],['define','b','two'],['language','de'],['queue','a b '*N],['flush']]", "[['language','fr'],['define','a','ah'],['voice','alto'],['reset-voice'],['queue','a '*N],['flush']]", "[['queue','  x  '*N],['flush']]", '[]']
expected = {1: [[[['fr', 'alto', 'A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 2: [[[['fr', 'alto', 'A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 3: [[[['fr', 'alto', 'A I A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 4: [[[['fr', 'alto', 'A I A I A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x    x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 5: [[[['fr', 'alto', 'A I A I A I A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second second second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa upper lower Aa upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b a b a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ah ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x    x    x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]]}[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	`[[['en', 'alto', 'A I '], ['en', 'bass', 'A I']], [], 'fr', 'bass', [['AI', 'A I']]]`	`[[['fr', 'alto', 'A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [['AI', 'A I']]]`	Failed
trace-2	`[[['en', 'default', 'second ']], [], 'en', 'default', [['a', 'second']]]`	`[[['en', 'default', 'second ']], [], 'en', 'default', [['a', 'second']]]`	Passed
trace-3	`[[['en', 'default', 'upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [['a', 'lower']]]`	`[[['en', 'default', 'upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [['a', 'lower']]]`	Passed
trace-4	`[[['en', 'default', 'a b ']], [], 'de', 'default', []]`	`[[['de', 'default', 'a b ']], [], 'de', 'default', []]`	Failed
trace-5	`[[['en', 'default', 'ah ']], [], 'fr', 'default', [['a', 'ah']]]`	`[[['fr', 'default', 'ah ']], [], 'fr', 'default', [['a', 'ah']]]`	Failed
trace-6	`[[['en', 'default', ' x ']], [], 'en', 'default', []]`	`[[['en', 'default', ' x ']], [], 'en', 'default', []]`	Passed
trace-7	`[[], [], 'en', 'default', []]`	`[[], [], 'en', 'default', []]`	Passed

SHA-256 / 59b19cf7bfe36c7267b2f7d584bc8bca700f1ee23db4972fb11e144d96099334

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(events):
    lang='en'; voice='default'; words={}; q=[]; spoken=[]
    for e in events:
        if e[0]=='language': lang=e[1]; words.clear()
        elif e[0]=='voice': voice=e[1]
        elif e[0]=='define': words[e[1]]=e[2]
        elif e[0]=='remove': words.pop(e[1],None)
        elif e[0]=='reset-voice': voice='default'
        elif e[0]=='queue':
            tokens=e[1].split(' ')
            rendered=' '.join(words.get(token,token) for token in tokens)
            q.append([lang,voice,rendered])
        elif e[0]=='flush':
            spoken.extend(q)
            q.clear()
    return [spoken,q,lang,voice,sorted(words.items())]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['language','fr'],['voice','alto'],['define','AI','A I'],['queue','AI '*N],['voice','bass'],['queue','AI'],['flush'],['flush']]", "[['define','a','first'],['define','a','second'],['queue','a '*N],['flush']]", "[['define','A','upper'],['define','a','lower'],['queue','A a Aa '*N],['remove','A'],['queue','A a'],['flush']]", "[['define','a','one'],['define','b','two'],['language','de'],['queue','a b '*N],['flush']]", "[['language','fr'],['define','a','ah'],['voice','alto'],['reset-voice'],['queue','a '*N],['flush']]", "[['queue','  x  '*N],['flush']]", '[]']
expected = {1: [[[['fr', 'alto', 'A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 2: [[[['fr', 'alto', 'A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 3: [[[['fr', 'alto', 'A I A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 4: [[[['fr', 'alto', 'A I A I A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x    x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]], 5: [[[['fr', 'alto', 'A I A I A I A I A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [('AI', 'A I')]], [[['en', 'default', 'second second second second second ']], [], 'en', 'default', [('a', 'second')]], [[['en', 'default', 'upper lower Aa upper lower Aa upper lower Aa upper lower Aa upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [('a', 'lower')]], [[['de', 'default', 'a b a b a b a b a b ']], [], 'de', 'default', []], [[['fr', 'default', 'ah ah ah ah ah ']], [], 'fr', 'default', [('a', 'ah')]], [[['en', 'default', '  x    x    x    x    x  ']], [], 'en', 'default', []], [[], [], 'en', 'default', []]]}[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	`[[['fr', 'alto', 'A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [['AI', 'A I']]]`	`[[['fr', 'alto', 'A I '], ['fr', 'bass', 'A I']], [], 'fr', 'bass', [['AI', 'A I']]]`	Passed
trace-2	`[[['en', 'default', 'second ']], [], 'en', 'default', [['a', 'second']]]`	`[[['en', 'default', 'second ']], [], 'en', 'default', [['a', 'second']]]`	Passed
trace-3	`[[['en', 'default', 'upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [['a', 'lower']]]`	`[[['en', 'default', 'upper lower Aa '], ['en', 'default', 'A lower']], [], 'en', 'default', [['a', 'lower']]]`	Passed
trace-4	`[[['de', 'default', 'a b ']], [], 'de', 'default', []]`	`[[['de', 'default', 'a b ']], [], 'de', 'default', []]`	Passed
trace-5	`[[['fr', 'default', 'ah ']], [], 'fr', 'default', [['a', 'ah']]]`	`[[['fr', 'default', 'ah ']], [], 'fr', 'default', [['a', 'ah']]]`	Passed
trace-6	`[[['en', 'default', ' x ']], [], 'en', 'default', []]`	`[[['en', 'default', ' x ']], [], 'en', 'default', []]`	Passed
trace-7	`[[], [], 'en', 'default', []]`	`[[], [], 'en', 'default', []]`	Passed

SHA-256 / cc3c5f88e712be31bee7fcc1a7b8d2635e7019fd867c73265eac54c973e204d7

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 2026-09-29T14:40:21.832536+00:00.

Case digest / e3b06192c28996dc454d656b1c7c92a7c79fb7ffdacb25f2cd04cf0046c264a6