Checks

• I added a descriptive title to this issue
• I have searched (google, github) for similar issues and couldn’t find anything
• I have read and followed the docs and still think this is a bug

On the newest pydantic and newest mypy (0.920) I get:

mypy .                                                 
pyproject.toml:1: error: Error importing plugin "pydantic.mypy": cannot import name TypeVarDef
Found 1 error in 1 file (errors prevented further checking)

Bug

Output of python -c "import pydantic.utils; print(pydantic.utils.version_info())":

             pydantic version: 1.8.2
            pydantic compiled: True
                 install path: /Users/USERNAME/opt/anaconda3/envs/ENVNAME/lib/python3.9/site-packages/pydantic
               python version: 3.9.7 (default, Sep 16 2021, 08:50:36)  [Clang 10.0.0 ]
                     platform: macOS-10.16-x86_64-i386-64bit
     optional deps. installed: ['dotenv', 'typing-extensions']

Related issues in mypy issue tracker: https://github.com/python/mypy/issues/11767