this is how my problem was solved => pip3 install setuptools-rust
If you want to check your list => pip3 list
i faced this problem while trying to install elastalert2
System informations
CentOS Linux release 7.9.2009 (Core)
Python 3.6.8
pip 21.3.1 from /usr/local/lib/python3.6/site-packages/pip (python 3.6)