* feat(asr): crash-isolated faster-whisper subprocess backend (Wave 4.2)
Native ASR engines (faster-whisper / CTranslate2) can segfault on GPU
teardown — a process-level crash that kills the whole backend. Running the
engine in a child process turns that into a failed job: the sidecar dies,
the parent raises a decorated error (engine id + device), and the next
request respawns a fresh sidecar.
- services/subprocess_asr.py: SubprocessASRBackend reuses
SubprocessBackend's wire protocol + lifecycle — including
respawn-on-dead-process (_spawn relaunches when the child isn't alive) and
GPU-slot acquire/release — adding a 'transcribe' op (the TTS 'generate'
surface is stubbed). IsolatedFasterWhisperBackend wraps faster-whisper
using the PARENT venv (already a dep — only the process boundary is new);
opt-in via OMNIVOICE_ASR_BACKEND=faster-whisper-isolated.
- engines/_asr_sidecar/main.py: the faster-whisper runner (stdlib wire
protocol; torch/CT2 import lazily so the ready handshake fits the timeout).
- engines/_echo/main.py: a 'transcribe' echo op so the round-trip + crash
recovery are testable without a real engine.
- asr_backend._REGISTRY is now a lazy dict (mirrors the TTS registry) so the
isolated backend lists/resolves without importing the subprocess stack
unless selected.
Tests (echo sidecar, stdlib-only): round-trip, single long-lived sidecar
across calls, crash-mid-transcribe → decorated error + backend healthy +
next call respawns, registry exposure, generate-not-supported.
Spec 7 / parity program Wave 4.2.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
* fix(asr): deterministic crash test + drift marker for lazy ASR registry (Wave 4.2 CI)
CI surfaced two issues:
- The echo crash test relied on the crash-AFTER-reply hook, whose reply
may still reach the parent (timing-dependent) — and a leaked
OMNIVOICE_ECHO_CRASH from a sibling subprocess test poisoned the
non-crash tests. Fix: a deterministic OMNIVOICE_ECHO_CRASH_NO_REPLY hook
that exits BEFORE replying (guaranteed dead pipe → decorated error), and
the asr fixture clears both crash envs so the round-trip/two-call tests
can't inherit a leak.
- check-docs-drift's _ASR_MARKER didn't match the new lazy registry line
(_LazyASRRegistry({); updated the marker + the self-test fixture.
Verified the no-reply crash hook by driving the sidecar directly
(reply=None, exit 1); drift self-test + real-repo check green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
* fix(asr): allowlist the 'segments' op so transcribe replies aren't dropped (Wave 4.2 CI)
The parent's PARENT_INBOUND_OPS frozenset gated inbound sidecar frames but
never included 'segments' — the ASR transcribe reply op. _recv() dropped the
frame as disallowed, tail-recursed, hit EOF, and returned None, so every
transcribe surfaced as a bogus 'sidecar crashed mid-transcription'. TTS
('audio') was allowlisted; ASR ('segments') was missed. Add it (and list
'transcribe' in the informational SIDECAR_INBOUND_OPS), update the exact-shape
allowlist test.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
