FAILURE MAP
← Case archive

FA-21551 / Assistive announcements / Open access

Enabling one voice re-enables every unavailable voice · case 01

The announcement trace violates the stated voice-negotiation contract.

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

ROOT CAUSE

Fault site: elif e[0]=='enable': disabled.discard(e[1]) is implemented as elif e[0]=='enable': disabled.clear()

THE FAILURE

Fault site: elif e[0]=='enable': disabled.discard(e[1]) is implemented as elif e[0]=='enable': disabled.clear()

Unsuccessful approach: The attempted repair substitutes elif e[0]=='enable': pass and still violates a regression oracle.

Case contract

Voice inventory rows are [id,language,local,quality,features]. Request [language,offline,required-features,preferred-id]. Selection excludes unavailable or missing-feature voices, honors exact preferred only among eligible, then ranks exact language before base-language before en fallback, local before remote, higher quality, then lexical ID. Add replaces same ID; remove marks unavailable; enable restores it. Return selected IDs or None, inventory IDs and disabled IDs.

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):
    voices={}; disabled=set(); out=[]
    for e in events:
        if e[0]=='add': voices[e[1]]=e[1:]
        elif e[0]=='remove': disabled.add(e[1])
        elif e[0]=='enable': disabled.clear()
        elif e[0]=='request':
            lang,offline,required,preferred=e[1:]
            rows=[v for k,v in voices.items() if k not in disabled]
            rows=[v for v in rows if not offline or v[2]]
            rows=[v for v in rows if set(required)<=set(v[4])]
            rows=[v for v in rows if v[1]==lang or v[1].split('-')[0]==lang.split('-')[0] or v[1]=='en']
            if not rows: out.append(None); continue
            def rank(v):
                language_rank=0 if v[1]==lang else (1 if v[1].split('-')[0]==lang.split('-')[0] else 2)
                return (v[0]!=preferred,language_rank,not v[2],-v[3],v[0])
            out.append(min(rows,key=rank)[0])
    return [out,list(voices),sorted(disabled)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['add','a','en',True,1,['marks']],['add','b','en',True,N+5,['marks','spell']],['request','en',True,['marks'],None]]", "[['add','a','fr',False,9,['marks']],['add','b','fr',True,1,['marks']],['request','fr',False,[],None],['request','fr',True,[],None],['request','fr',False,[],'a']]", "[['add','z','fr-CA',True,1,[]],['add','a','fr',True,9,[]],['add','e','en',True,1,[]],['request','fr-CA',False,[],None],['request','fr-BE',False,[],None],['request','fr-CA',False,[],'e']]", "[['add','a','en',True,9,['marks']],['add','b','en',True,2,['marks','spell','pause']],['request','en',True,['marks','spell'],None],['add','a','en',True,10,['marks','spell']],['request','en',True,['spell'],None]]", "[['add','a','en',True,N+5,[]],['add','b','en',True,1,[]],['remove','a'],['request','en',False,[],None],['remove','b'],['enable','b'],['request','en',False,[],None]]", "[['add','remote','ja',False,N,[]],['request','ja',False,[],None],['request','ja',True,[],None],['request','de',False,[],'remote']]", "[['request','en',True,[],None]]"]
expected = {1: [[['b'], ['a', 'b'], []], [['b', 'b', 'a'], ['a', 'b'], []], [['z', 'a', 'e'], ['z', 'a', 'e'], []], [['b', 'a'], ['a', 'b'], []], [['b', 'b'], ['a', 'b'], ['a']], [['remote', None, None], ['remote'], []], [[None], [], []]], 2: [[['b'], ['a', 'b'], []], [['b', 'b', 'a'], ['a', 'b'], []], [['z', 'a', 'e'], ['z', 'a', 'e'], []], [['b', 'a'], ['a', 'b'], []], [['b', 'b'], ['a', 'b'], ['a']], [['remote', None, None], ['remote'], []], [[None], [], []]], 3: [[['b'], ['a', 'b'], []], [['b', 'b', 'a'], ['a', 'b'], []], [['z', 'a', 'e'], ['z', 'a', 'e'], []], [['b', 'a'], ['a', 'b'], []], [['b', 'b'], ['a', 'b'], ['a']], [['remote', None, None], ['remote'], []], [[None], [], []]], 4: [[['b'], ['a', 'b'], []], [['b', 'b', 'a'], ['a', 'b'], []], [['z', 'a', 'e'], ['z', 'a', 'e'], []], [['b', 'a'], ['a', 'b'], []], [['b', 'b'], ['a', 'b'], ['a']], [['remote', None, None], ['remote'], []], [[None], [], []]], 5: [[['b'], ['a', 'b'], []], [['b', 'b', 'a'], ['a', 'b'], []], [['z', 'a', 'e'], ['z', 'a', 'e'], []], [['b', 'a'], ['a', 'b'], []], [['b', 'b'], ['a', 'b'], ['a']], [['remote', None, None], ['remote'], []], [[None], [], []]]}[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[['b'], ['a', 'b'], []][['b'], ['a', 'b'], []]Passed
trace-2[['b', 'b', 'a'], ['a', 'b'], []][['b', 'b', 'a'], ['a', 'b'], []]Passed
trace-3[['z', 'a', 'e'], ['z', 'a', 'e'], []][['z', 'a', 'e'], ['z', 'a', 'e'], []]Passed
trace-4[['b', 'a'], ['a', 'b'], []][['b', 'a'], ['a', 'b'], []]Passed
trace-5[['b', 'a'], ['a', 'b'], []][['b', 'b'], ['a', 'b'], ['a']]Failed
trace-6[['remote', None, None], ['remote'], []][['remote', None, None], ['remote'], []]Passed
trace-7[[None], [], []][[None], [], []]Passed

SHA-256 / e438bb7c7d3ac3d1acbc23b99aa1f47e5f5f4f0673f6e8dd1ab676eba095aaf1

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(events):
    voices={}; disabled=set(); out=[]
    for e in events:
        if e[0]=='add': voices[e[1]]=e[1:]
        elif e[0]=='remove': disabled.add(e[1])
        elif e[0]=='enable': pass
        elif e[0]=='request':
            lang,offline,required,preferred=e[1:]
            rows=[v for k,v in voices.items() if k not in disabled]
            rows=[v for v in rows if not offline or v[2]]
            rows=[v for v in rows if set(required)<=set(v[4])]
            rows=[v for v in rows if v[1]==lang or v[1].split('-')[0]==lang.split('-')[0] or v[1]=='en']
            if not rows: out.append(None); continue
            def rank(v):
                language_rank=0 if v[1]==lang else (1 if v[1].split('-')[0]==lang.split('-')[0] else 2)
                return (v[0]!=preferred,language_rank,not v[2],-v[3],v[0])
            out.append(min(rows,key=rank)[0])
    return [out,list(voices),sorted(disabled)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = ["[['add','a','en',True,1,['marks']],['add','b','en',True,N+5,['marks','spell']],['request','en',True,['marks'],None]]", "[['add','a','fr',False,9,['marks']],['add','b','fr',True,1,['marks']],['request','fr',False,[],None],['request','fr',True,[],None],['request','fr',False,[],'a']]", "[['add','z','fr-CA',True,1,[]],['add','a','fr',True,9,[]],['add','e','en',True,1,[]],['request','fr-CA',False,[],None],['request','fr-BE',False,[],None],['request','fr-CA',False,[],'e']]", "[['add','a','en',True,9,['marks']],['add','b','en',True,2,['marks','spell','pause']],['request','en',True,['marks','spell'],None],['add','a','en',True,10,['marks','spell']],['request','en',True,['spell'],None]]", "[['add','a','en',True,N+5,[]],['add','b','en',True,1,[]],['remove','a'],['request','en',False,[],None],['remove','b'],['enable','b'],['request','en',False,[],None]]", "[['add','remote','ja',False,N,[]],['request','ja',False,[],None],['request','ja',True,[],None],['request','de',False,[],'remote']]", "[['request','en',True,[],None]]"]
expected = {1: [[['b'], ['a', 'b'], []], [['b', 'b', 'a'], ['a', 'b'], []], [['z', 'a', 'e'], ['z', 'a', 'e'], []], [['b', 'a'], ['a', 'b'], []], [['b', 'b'], ['a', 'b'], ['a']], [['remote', None, None], ['remote'], []], [[None], [], []]], 2: [[['b'], ['a', 'b'], []], [['b', 'b', 'a'], ['a', 'b'], []], [['z', 'a', 'e'], ['z', 'a', 'e'], []], [['b', 'a'], ['a', 'b'], []], [['b', 'b'], ['a', 'b'], ['a']], [['remote', None, None], ['remote'], []], [[None], [], []]], 3: [[['b'], ['a', 'b'], []], [['b', 'b', 'a'], ['a', 'b'], []], [['z', 'a', 'e'], ['z', 'a', 'e'], []], [['b', 'a'], ['a', 'b'], []], [['b', 'b'], ['a', 'b'], ['a']], [['remote', None, None], ['remote'], []], [[None], [], []]], 4: [[['b'], ['a', 'b'], []], [['b', 'b', 'a'], ['a', 'b'], []], [['z', 'a', 'e'], ['z', 'a', 'e'], []], [['b', 'a'], ['a', 'b'], []], [['b', 'b'], ['a', 'b'], ['a']], [['remote', None, None], ['remote'], []], [[None], [], []]], 5: [[['b'], ['a', 'b'], []], [['b', 'b', 'a'], ['a', 'b'], []], [['z', 'a', 'e'], ['z', 'a', 'e'], []], [['b', 'a'], ['a', 'b'], []], [['b', 'b'], ['a', 'b'], ['a']], [['remote', None, None], ['remote'], []], [[None], [], []]]}[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[['b'], ['a', 'b'], []][['b'], ['a', 'b'], []]Passed
trace-2[['b', 'b', 'a'], ['a', 'b'], []][['b', 'b', 'a'], ['a', 'b'], []]Passed
trace-3[['z', 'a', 'e'], ['z', 'a', 'e'], []][['z', 'a', 'e'], ['z', 'a', 'e'], []]Passed
trace-4[['b', 'a'], ['a', 'b'], []][['b', 'a'], ['a', 'b'], []]Passed
trace-5[['b', None], ['a', 'b'], ['a', 'b']][['b', 'b'], ['a', 'b'], ['a']]Failed
trace-6[['remote', None, None], ['remote'], []][['remote', None, None], ['remote'], []]Passed
trace-7[[None], [], []][[None], [], []]Passed

SHA-256 / 35dca309e2bab3cfddf99882781d837ee4c0d41347231f57108c34b7b5ddf9fe

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 7 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 2026-09-29T14:40:30.250901+00:00.

Case digest / c8f2cbe804a50bf2d6eb57ea718248eb340c402e3381b4b1e09249a14fa41a38