I am writing because I am having trouble installing Pyomo using pip
on Python 3.6 on Mac OSX 10.14
I\'m following the installation instructions here.
I got the problem too (in Ubuntu 18.04).
Try installing it from the git project (https://github.com/Pyomo/pyomo):
In Ubuntu 18.04:
git clone https://github.com/Pyomo/pyomo.git
python3 pyomo/scripts/get_pyomo_extras.py
Use the corresponding commands for Mac OSX (I had never used it).
I hope that it works for you.