check that GNU compliler tools are installed:

• https://superuser.com/questions/383580/how-to-install-autoconf-automake-and-related-tools-on-mac-os-x-from-source

check that xcode developer tools are installed

• if not an "inactive developer path error" will be raised (fix if recently ugraded to OS X Mojave: https://apple.stackexchange.com/questions/254380/macos-mojave-invalid-active-developer-path)

follow quick start installation instructions at https://github.com/ViennaRNA/ViennaRNA

NOTE: ./configure option for python 3: ./configure --disable-openmp --without-perl --without-python

if RNA isn't found when you run >import RNA, then go to your .bash-profile and then add the location of the python 3 site packages to your PYTHONPATH variable https://leemendelowitz.github.io/blog/how-does-python-find-packages.html