Prerequisite steps for FreeBSD users

This command should provide required packages for FreeBSD installation:

sudo pkg install cmake cython eigen3 harfbuzz opus-tools opusfile png py-numpy py-pillow py-pygments pylint python qt5 sdl2 sdl2_image

You will also need nyan and its dependencies.

clang is the base compiler however, it is possible to use either any version of gcc>=7 or any other version of clang present in pkg:

sudo pkg install gcc

Select the one to be used by ./configure --help.