ai-agents-tool-call-serializat-pydantic-validation-error-cannot-pickle-pydantic-c-544a8b2b

THEN Replace deepcopy with shallow copy on the pydantic object in the logging setup to avoid serialization failure. Specifically, in litellm's logging initialization, change copy.deepcopy(messages) to a shallow copy or use a custom serialization method that excludes the non-picklable ValidatorIterator. This fix is reported to resolve the issue for tools returning lists.

// In litellm/litellm_core_utils/litellm_logging.py, line 282, change
// self.messages = copy.deepcopy(messages)
// to
// self.messages = copy.copy(messages)  # shallow copy avoids pickle error