AttributeError: 'NoneType' object has no attribute 'prompt_tokens'

[Tangyueming311]

I got this confusing bug.

Generating proposal 1/20
Failed to generate proposal:
Traceback (most recent call last):
File "/root/AI-Scientist-v2/ai_scientist/perform_ideation_temp_free.py", line 173, in generate_temp_free_idea
response_text, msg_history = get_response_from_llm(
^^^^^^^^^^^^^^^^^^^^^^
File "/root/miniconda3/envs/ai_scientist/lib/python3.11/site-packages/backoff/_sync.py", line 105, in retry
ret = target(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^
File "/root/AI-Scientist-v2/ai_scientist/../ai_scientist/llm.py", line 266, in get_response_from_llm
response = make_llm_call(
^^^^^^^^^^^^^^
File "/root/AI-Scientist-v2/ai_scientist/../ai_scientist/utils/token_tracker.py", line 201, in sync_wrapper
result.usage.prompt_tokens,
^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'prompt_tokens'