with (import ./nixpkgs.nix);
let
  ruby_version = import ./ruby-version.nix;
  gems = bundlerEnv {
    name = "advent-of-code";
    ruby = ruby_version;
    gemdir = ./.;
  };
in stdenv.mkDerivation {
  name = "qa-mds";
  buildInputs = [ gems gems.wrappedRuby ];
  shellHook = ''
      if ! [ $NO_CHANGE_PROMPT ]; then
        export PS1='\[\033[1;31m\]λ\[\033[0m\] '
        export PS2='\[\033[1;31m\]|\[\033[0m\] '
      fi
  '';
}