Add debug logging to synthesis pipeline to trace hang

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server.py

@@ -119,32 +119,40 @@ class KokoroEventHandler(AsyncEventHandler):
 
         try:
             chunk_queue: asyncio.Queue = asyncio.Queue()
-            loop = asyncio.get_event_loop()
+            loop = asyncio.get_running_loop()
 
             def _generate():
+                chunk_count = 0
                 try:
+                    _LOGGER.debug("Pipeline thread started")
                     for _, _, audio in self.pipeline(text, voice=voice_name, speed=speed):
                         if audio is None:
                             continue
                         # float32 [-1, 1] → int16
                         audio_np = audio.cpu().numpy() if hasattr(audio, 'cpu') else audio
                         pcm = (np.clip(audio_np, -1.0, 1.0) * 32767).astype(np.int16)
-                        asyncio.run_coroutine_threadsafe(
-                            chunk_queue.put(pcm.tobytes()), loop
-                        )
+                        chunk_count += 1
+                        _LOGGER.debug("Queueing chunk %d (%d bytes)", chunk_count, len(pcm.tobytes()))
+                        fut = asyncio.run_coroutine_threadsafe(chunk_queue.put(pcm.tobytes()), loop)
+                        fut.result()  # propagate any queue errors
+                    _LOGGER.debug("Pipeline finished, %d chunks generated", chunk_count)
                 except Exception as exc:
-                    asyncio.run_coroutine_threadsafe(chunk_queue.put(exc), loop)
+                    _LOGGER.exception("Pipeline thread error")
+                    asyncio.run_coroutine_threadsafe(chunk_queue.put(exc), loop).result()
                 finally:
-                    asyncio.run_coroutine_threadsafe(chunk_queue.put(None), loop)
+                    asyncio.run_coroutine_threadsafe(chunk_queue.put(None), loop).result()
 
             self.executor.submit(_generate)
 
+            chunks_sent = 0
             while True:
                 item = await chunk_queue.get()
                 if item is None:
                     break
                 if isinstance(item, Exception):
                     raise item
+                chunks_sent += 1
+                _LOGGER.debug("Sending audio chunk %d", chunks_sent)
                 await self.write_event(
                     AudioChunk(
                         rate=KOKORO_SAMPLE_RATE,
@@ -153,6 +161,7 @@ class KokoroEventHandler(AsyncEventHandler):
                         audio=item,
                     ).event()
                 )
+            _LOGGER.info("Synthesis complete, sent %d chunks", chunks_sent)
         except Exception:
             _LOGGER.exception("Error during synthesis")
         finally:
@@ -168,7 +177,7 @@ async def main() -> None:
     args = parser.parse_args()
 
     logging.basicConfig(
-        level=logging.DEBUG if args.debug else logging.INFO,
+        level=logging.DEBUG,
         format="%(asctime)s %(levelname)s %(name)s: %(message)s",
     )