Command \"/usr/bin/python -u -c \"import setuptools, tokenize;__file__=\'/private/tmp/pip-build-J1I0ox/pymssql/setup.py\';f=getattr(tokenize, \'open\', open)(__file__);c
This link ended up solving my problem. For anyone else having these issues, this sequence of commands worked for me.
brew uninstall --force freetds brew install freetds@0.91 brew link --force freetds@0.91 pip install pymssql