fix(chat): retry silent rounds with think=True before falling back

Qwen3's tool-call tokens sometimes fail to parse into either content
or tool_calls, burning output tokens and producing empty bubbles.
Detect the signature within a round (empty content, no tool calls,
eval_count > 0) and re-run the same round once with reasoning mode
enabled, which emits more reliable output. The post-loop fallback
remains as the final catch.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
2026-04-15 18:22:28 -04:00
parent ba0cb07c91
commit 058d6089b1
+126 -95
View File
@@ -410,103 +410,134 @@ async def run_generation(
buf.append_event("status", {"status": "Generating response..." if _round == 0 else "Composing response..."})
t_stream = time.monotonic()
async for chunk in _stream_with_retry(messages, model, tools, think, num_ctx=num_ctx):
if buf.cancel_event.is_set():
cancelled = True
round_content_start = len(buf.content_so_far)
round_tokens_start = timing.get("output_tokens") or 0
effective_think = think
retried_with_think = False
while True:
async for chunk in _stream_with_retry(messages, model, tools, effective_think, num_ctx=num_ctx):
if buf.cancel_event.is_set():
cancelled = True
break
if chunk.type == "thinking":
if timing["first_token_ms"] is None:
timing["first_token_ms"] = int((time.monotonic() - t_start) * 1000)
buf.append_event("thinking_chunk", {"chunk": chunk.content})
elif chunk.type == "content":
if timing["ttft_ms"] is None:
now_ms = int((time.monotonic() - t_start) * 1000)
timing["ttft_ms"] = now_ms
if timing["first_token_ms"] is None:
# No thinking phase occurred — first token IS content.
timing["first_token_ms"] = now_ms
else:
# Thinking phase duration = gap between first thinking
# token and first content token.
timing["thinking_ms"] = now_ms - timing["first_token_ms"]
buf.content_so_far += chunk.content
clean = _TOOL_CALL_MARKER.sub("", chunk.content)
if clean:
buf.append_event("chunk", {"chunk": clean})
now = time.monotonic()
if now - last_flush >= DB_FLUSH_INTERVAL:
try:
await _update_message(msg_id, buf.content_so_far, "generating")
except Exception:
logger.warning("Failed periodic flush for message %d", msg_id, exc_info=True)
last_flush = now
elif chunk.type == "done":
if chunk.prompt_tokens is not None:
timing["prompt_tokens"] = (timing["prompt_tokens"] or 0) + chunk.prompt_tokens
if chunk.output_tokens is not None:
timing["output_tokens"] = (timing["output_tokens"] or 0) + chunk.output_tokens
elif chunk.type == "tool_calls" and chunk.tool_calls:
logger.info("Round %d: model returned %d tool call(s)", _round, len(chunk.tool_calls))
for tc in chunk.tool_calls:
fn = tc.get("function", {})
tool_name = fn.get("name", "")
arguments = fn.get("arguments", {})
logger.info("Executing tool: %s(%s)", tool_name, json.dumps(arguments)[:200])
buf.append_event("status", {"status": f"{_TOOL_LABELS.get(tool_name, 'Working')}..."})
t_tool = time.monotonic()
if tool_name == "research_topic":
topic = arguments.get("topic", "")
try:
note = await run_research_pipeline(topic, user_id, model, buf, project_id=workspace_project_id)
result = {
"success": True,
"type": "research_note",
"data": {"id": note.id, "title": note.title},
}
done_text = (
f"\n\n---\n\nResearch complete! I've compiled a note: "
f"**[{note.title}](/notes/{note.id})**."
)
buf.append_event("chunk", {"chunk": done_text})
buf.content_so_far += done_text
except Exception as e:
logger.exception("Research pipeline failed for topic: %s", topic)
err_msg = str(e) or f"{type(e).__name__}: unexpected error"
result = {"success": False, "error": err_msg}
err_text = f"\nResearch failed: {err_msg}"
buf.append_event("chunk", {"chunk": err_text})
buf.content_so_far += err_text
research_completed = True
else:
result = await execute_tool(
user_id, tool_name, arguments,
conv_id=conv_id,
workspace_project_id=workspace_project_id,
)
# Capture RAG scope change for SSE done event
if result.get("type") == "rag_scope_set" and result.get("success"):
new_rag_scope = arguments.get("project_id")
new_rag_scope_label = result.get("scope_label")
timing["tools"].append({"name": tool_name, "ms": int((time.monotonic() - t_tool) * 1000)})
logger.info("Tool %s result: success=%s", tool_name, result.get("success"))
tool_record = {
"function": tool_name,
"arguments": arguments,
"result": result,
"status": "success" if result.get("success") else "error",
}
round_tool_calls.append(tool_record)
all_tool_calls.append(tool_record)
buf.append_event("tool_call", {"tool_call": tool_record})
if cancelled:
break
if chunk.type == "thinking":
if timing["first_token_ms"] is None:
timing["first_token_ms"] = int((time.monotonic() - t_start) * 1000)
buf.append_event("thinking_chunk", {"chunk": chunk.content})
elif chunk.type == "content":
if timing["ttft_ms"] is None:
now_ms = int((time.monotonic() - t_start) * 1000)
timing["ttft_ms"] = now_ms
if timing["first_token_ms"] is None:
# No thinking phase occurred — first token IS content.
timing["first_token_ms"] = now_ms
else:
# Thinking phase duration = gap between first thinking
# token and first content token.
timing["thinking_ms"] = now_ms - timing["first_token_ms"]
buf.content_so_far += chunk.content
clean = _TOOL_CALL_MARKER.sub("", chunk.content)
if clean:
buf.append_event("chunk", {"chunk": clean})
now = time.monotonic()
if now - last_flush >= DB_FLUSH_INTERVAL:
try:
await _update_message(msg_id, buf.content_so_far, "generating")
except Exception:
logger.warning("Failed periodic flush for message %d", msg_id, exc_info=True)
last_flush = now
elif chunk.type == "done":
if chunk.prompt_tokens is not None:
timing["prompt_tokens"] = (timing["prompt_tokens"] or 0) + chunk.prompt_tokens
if chunk.output_tokens is not None:
timing["output_tokens"] = (timing["output_tokens"] or 0) + chunk.output_tokens
elif chunk.type == "tool_calls" and chunk.tool_calls:
logger.info("Round %d: model returned %d tool call(s)", _round, len(chunk.tool_calls))
for tc in chunk.tool_calls:
fn = tc.get("function", {})
tool_name = fn.get("name", "")
arguments = fn.get("arguments", {})
logger.info("Executing tool: %s(%s)", tool_name, json.dumps(arguments)[:200])
buf.append_event("status", {"status": f"{_TOOL_LABELS.get(tool_name, 'Working')}..."})
t_tool = time.monotonic()
if tool_name == "research_topic":
topic = arguments.get("topic", "")
try:
note = await run_research_pipeline(topic, user_id, model, buf, project_id=workspace_project_id)
result = {
"success": True,
"type": "research_note",
"data": {"id": note.id, "title": note.title},
}
done_text = (
f"\n\n---\n\nResearch complete! I've compiled a note: "
f"**[{note.title}](/notes/{note.id})**."
)
buf.append_event("chunk", {"chunk": done_text})
buf.content_so_far += done_text
except Exception as e:
logger.exception("Research pipeline failed for topic: %s", topic)
err_msg = str(e) or f"{type(e).__name__}: unexpected error"
result = {"success": False, "error": err_msg}
err_text = f"\nResearch failed: {err_msg}"
buf.append_event("chunk", {"chunk": err_text})
buf.content_so_far += err_text
research_completed = True
else:
result = await execute_tool(
user_id, tool_name, arguments,
conv_id=conv_id,
workspace_project_id=workspace_project_id,
)
# Capture RAG scope change for SSE done event
if result.get("type") == "rag_scope_set" and result.get("success"):
new_rag_scope = arguments.get("project_id")
new_rag_scope_label = result.get("scope_label")
timing["tools"].append({"name": tool_name, "ms": int((time.monotonic() - t_tool) * 1000)})
logger.info("Tool %s result: success=%s", tool_name, result.get("success"))
tool_record = {
"function": tool_name,
"arguments": arguments,
"result": result,
"status": "success" if result.get("success") else "error",
}
round_tool_calls.append(tool_record)
all_tool_calls.append(tool_record)
buf.append_event("tool_call", {"tool_call": tool_record})
round_content_added = len(buf.content_so_far) - round_content_start
round_tokens_added = (timing.get("output_tokens") or 0) - round_tokens_start
if (
not round_tool_calls
and round_content_added == 0
and round_tokens_added > 0
and not effective_think
and not retried_with_think
):
# Silent round: qwen3's tool-call tokens sometimes aren't
# parsed into content or tool_calls. Retry once with
# think=True — reasoning mode produces more reliable output.
logger.warning(
"Silent round %d for conv %d (tokens=%d); retrying with think=True",
_round, conv_id, round_tokens_added,
)
buf.append_event("status", {"status": "Retrying with reasoning enabled..."})
effective_think = True
retried_with_think = True
continue
break
timing["generation_ms"] = int((time.monotonic() - t_stream) * 1000)