I'm having issues installing mpi4py on macOS 10.14.3, using python 3.6.6. I installed I had to install open-mpi (v4.0.1), which worked; I was to run the test as suggested in this post: https://stackoverflow.com/questions/42703861/how-to-use-mpi-on-mac-os-x
I still cannot install mpi4py (tried 3.0.1, 3.0.0 and 2.0.0, all fail). It starts with a linker command that fails (for the llmpe library, and others), and then reports on unexpected expressions and outdated symbols in the code. The output in full is attached as a text file. Please let me know if you need more information from my side, or if you have suggestions how to address this.