Mac is a good computer but seems to be weird when you are attacking some install.
I had error installing the PostGreSQL drivers for python.
Typing a :
$ pipenv install psycopg2
$ pip install psycopg2 was leading to compilation error...
Problems seems to be with Mac (as usual) and Path. (as Usual)
Then was solved on my side doing that :
1 - I presume you have PostGreSQL installed via a homebrew install ...
if not :
$ brew install postgresql
2 - I presume you have started PostGree too...
If not, :
$ pg_ctl -D /usr/local/var/postgres start
3 - Install Opensll
$ brew install openssl
If you have already installed it, re-install
$ brew reinstall openssl
4 - Find the path of pg_config
$ find / -name pg_config 2>/dev/nul
5 - Check something like my path :
$ export PATH=$PATH:/usr/local/Cellar/postgresql/11.5_1/bin/pg_config
6 - Do the same thing with the lib ssl :
$ export LIBRARY_PATH=$LIBRARY_PATH:/usr/local/opt/openssl/lib/
Ok now, you should be OK typing :
$ pipenv install psycopg2 if you use pipenv
$ pip install psycopg2
it could pip3 instead of pip if you are not working under virtual environnement and you have installed the python 3 version keeping the python2 on the Mac.
Inside a virtual environnement, the pip is linked to python3 by default.