nixpkgs/pkgs/development/tools/rufo/gemset.nix

{
  rufo = {
    groups = ["default"];
    platforms = [];
    source = {
      remotes = ["https://rubygems.org"];
      sha256 = "11nm1vzr3vd85yy4rd7ndrrx1ygm3m2jmw9r0b9lfxlj8rc1rip2";
      type = "gem";
    };
    version = "0.16.2";
  };
}