[Bug] TypeError in models.py: "can only concatenate str (not 'NoneType') to str" when using Ollama

[librepensador-coder]

Description

When using Agent Zero v0.9.7-10 with Ollama models, the memory recall system fails with a TypeError because reasoning_delta can be None.

Error

Traceback (most recent call last):
  File "/a0/python/extensions/message_loop_prompts_after/_50_recall_memories.py", line 146, in search_memories
    filter = await self.agent.call_utility_model(
  File "/a0/agent.py", line 719, in call_utility_model
    response, _reasoning = await call_data["model"].unified_call(
  File "/a0/models.py", line 545, in unified_call
    output = result.add_chunk(parsed)
  File "/a0/models.py", line 118, in add_chunk
    self.reasoning += processed_chunk["reasoning_delta"]
TypeError: can only concatenate str (not "NoneType") to str

Environment

• Agent Zero version: v0.9.7-10
• Model provider: Ollama
• Chat model: qwen2.5:32b
• Utility model: qwen2.5:7b / qwen2.5:32b
• OS: Windows 11 (Docker)

Root Cause

In models.py line 118-119, the code assumes processed_chunk["reasoning_delta"] and processed_chunk["response_delta"] are always strings, but Ollama can return None.

Proposed Fix

# Line 118-119 in models.py
self.reasoning += processed_chunk["reasoning_delta"] or ""
self.response += processed_chunk["response_delta"] or ""

Workaround

Manually patch the container:

docker exec agent-zero sh -c "sed -i 's/self.reasoning += processed_chunk\[\"reasoning_delta\"\]$/self.reasoning += processed_chunk[\"reasoning_delta\"] or \"\"/g' /a0/models.py && sed -i 's/self.response += processed_chunk\[\"response_delta\"\]$/self.response += processed_chunk[\"response_delta\"] or \"\"/g' /a0/models.py"
docker restart agent-zero