[Bug]: UserWarning: Pydantic serializer warnings: PydanticSerializationUnexpectedValue(Expected 9 fields but got 6: ... #11759
Description
What happened?
When upgrading from LiteLLM 1.72.4 to 1.72.6, I now get a pydantic Serialization warning about unexpected values.
It's triggered by this code:
I'm using model_id="gpt-4.1-mini" and the acompletion API
Found while working on mozilla-ai/any-agent#370
https://github.com/mozilla-ai/any-llm
Relevant log output
/Users/nbrake/scm/any-agent/.venv/lib/python3.13/site-packages/pydantic/main.py:464: UserWarning: Pydantic serializer warnings:
PydanticSerializationUnexpectedValue(Expected 9 fields but got 6: Expected `Message` - serialized value may not be as expected [input_value=Message(content=None, rol...: None}, annotations=[]), input_type=Message])
PydanticSerializationUnexpectedValue(Expected `StreamingChoices` - serialized value may not be as expected [input_value=Choices(finish_reason='to...ider_specific_fields={}), input_type=Choices])
return self.__pydantic_serializer__.to_python(Are you a ML Ops Team?
No
What LiteLLM version are you on ?
1.72.6