Allow OmniVoice slow sidecar startup (#1743)

Fixes #1711.\n\nGives only the OmniVoice subprocess a 120-second readiness budget while retaining the shared 30-second default for all other sidecars, with regression coverage.

CHANGELOG.md

@@ -27,6 +27,7 @@ the frozen-backend fallback mirror it for their toolchains.
 
 ### Fixed
 
+- OmniVoice subprocess startup now allows slow packaged Windows Python runtimes to signal readiness before termination (#1711)
 - SRT files selected during source analysis now wait for speaker cloning, then replace transcript text without losing voices (#1709)
 - Windows MSI deployments can now prohibit WebView2 bootstrap with `DISABLEWEBVIEW2BOOTSTRAP=1`, and `AUTOLAUNCHAPP=0` reliably suppresses first launch (#1714)
 - Subtitle rows now provide 100 ms timing steppers and flag adjacent overlaps without requiring precise timeline dragging (#1710)

backend/engines/omnivoice_subprocess/__init__.py

@@ -52,6 +52,11 @@ class OmniVoiceSubprocessBackend(SubprocessBackend):
     # Match OmniVoiceBackend: the measured floor below which a render that
     # should take seconds runs for minutes (the #1226/#1222 4 GB reports).
     min_vram_gb = 6.0
+    # Packaged Windows hosts can spend more than the base 30 seconds starting
+    # the shared Python runtime before this stdlib-only sidecar emits ready.
+    # Keep the bound below the 300-second generation budget while avoiding the
+    # repeated false kill captured in #1711.
+    spawn_ready_timeout_s = 120.0
 
     @classmethod
     def is_available(cls) -> tuple[bool, str]:

backend/services/subprocess_backend.py

@@ -363,6 +363,7 @@ class SubprocessBackend(TTSBackend):
     # be a different class object from the one the subclass closed over.
     # A duck-typed marker survives that.
     _is_subprocess_isolated: bool = True
+    spawn_ready_timeout_s: float = SPAWN_READY_TIMEOUT_S
 
     # Generation happens in the sidecar: parent-side accelerator counters
     # can't see its allocations (see TTSBackend.runs_out_of_process).
@@ -524,7 +525,7 @@ class SubprocessBackend(TTSBackend):
         # Block on the ready handshake. A sidecar that fails to emit ready
         # within SPAWN_READY_TIMEOUT_S is killed and the failure is raised.
         try:
-            frame = self._recv_with_timeout(SPAWN_READY_TIMEOUT_S)
+            frame = self._recv_with_timeout(self.spawn_ready_timeout_s)
         except Exception:
             self._force_kill()
             raise

backend/tests/test_omnivoice_subprocess.py

@@ -273,6 +273,42 @@ def test_omnivoice_subprocess_recv_timeout_overrides_default():
     assert b.recv_timeout_s == 300.0  # aligns with the generate budget
 
 
+def test_omnivoice_subprocess_has_longer_spawn_budget_than_other_sidecars():
+    assert _PlainBackend.spawn_ready_timeout_s == 30.0
+    assert OmniVoiceSubprocessBackend.spawn_ready_timeout_s == 120.0
+
+
+def test_spawn_uses_backend_specific_ready_timeout(monkeypatch, tmp_path):
+    _use_stub(monkeypatch, tmp_path / "unused.py")
+    backend = OmniVoiceSubprocessBackend()
+    observed = []
+
+    class StubProcess:
+        stderr = io.BytesIO()
+
+        @staticmethod
+        def poll():
+            return None
+
+    monkeypatch.setattr(
+        "services.subprocess_backend.spawn_owned",
+        lambda *_args, **_kwargs: StubProcess(),
+    )
+    monkeypatch.setattr(
+        backend,
+        "_recv_with_timeout",
+        lambda timeout: observed.append(timeout) or {"op": "ready"},
+    )
+    monkeypatch.setattr("services.subprocess_backend._ensure_reaper_running", lambda: None)
+
+    try:
+        backend._spawn()
+    finally:
+        backend._proc = None
+
+    assert observed == [120.0]
+
+
 def test_omnivoice_subprocess_recv_timeout_env_override(monkeypatch):
     monkeypatch.setenv("OMNIVOICE_SIDECAR_RECV_TIMEOUT_S", "120")
     assert OmniVoiceSubprocessBackend().recv_timeout_s == 120.0