Nix flake that packages ratpac-two (RAT, Plus Additional Codes v2), a Geant4+ROOT simulation framework.
nix build has been tested successfully on x86_64-linux, but the resulting package still needs to be exercised on actual ratpac simulation code to be fully verified.
Initialize a dev shell template in a new project directory:
nix flake init -t github:ewtodd/ratpac-env --refresh