The fonts will be build with fontra compile, we need as requirement
fontra.git
fontra-rcjk.git => this is the backend that read .rcjk format
fontra-compile.git
fonttools
Create your virtual environment with your terminal with:
cd /your/repository/directory
source setupvenv.sh
To build the fonts, run the command line
sh build_fonts.sh
It will create at the root of the repository a folder build, containing the logs and a ttf folder with the fonts