Error when running make.sh

[mglymour]

When I run bash make.sh during the installation, I get the following error:

Traceback (most recent call last):
File "setup.py", line 11, in
from Cython.Build import cythonize
ImportError: No module named Cython.Build
Traceback (most recent call last):
File "setup.py", line 11, in
from Cython.Build import cythonize
ImportError: No module named Cython.Build
P-CG09-ML3:get_mask user$ which cython
P-CG09-ML3:get_mask user$ bash make.sh
Traceback (most recent call last):
File "setup.py", line 11, in
from Cython.Build import cythonize
ImportError: No module named Cython.Build
Traceback (most recent call last):
File "setup.py", line 11, in
from Cython.Build import cythonize
ImportError: No module named Cython.Build

I have cython installed. My machine is a Mac, running Mojave 10.14.6.