help!Why can't my vllm work?

[ftelhj]

I do install vllm==0.1.4,but it cant't run
ImportError: cannot import name 'RootModel' from 'pydantic' (/data/sub3/miniconda3/envs/wzc/lib/python3.9/site-packages/pydantic/init.cpython-39-x86_64-linux-gnu.so)