{
  outputs = { self, nixpkgs, ... }: let
    app = pkgs: let
      pkg = env.pkgs.buildPythonPackage {
        pname = "r24";
        version = "0.1";
        pyproject = true;
        src = ./.;
        dontWrapPythonPrograms = true;
  
        propagatedBuildInputs = with env.pkgs; [
          setuptools
          django
        ];
      };
      env = pkgs.python3.withPackages (_: [ pkg ]);
      wrapper = pkgs.writeShellScript "r24" ''
        exec ${env.interpreter} ${pkg.outPath}/bin/"''$(basename "''${0}")" "''${@}"
      '';
      result =  pkgs.runCommand "r24" { buildInputs = [ pkg ]; } ''
        mkdir -p ''${out}/bin
        for x in ${pkg}/bin/*; do
          [[ -x ''${x} ]] || continue
          ln -sf ${wrapper} ''${out}/bin/''${x##*/}
        done
      '';
    in result;

    packages = system: pkgs: {
      r24 = app pkgs;
    };
  in {
    packages = builtins.mapAttrs packages nixpkgs.legacyPackages;
    defaultPackage = builtins.mapAttrs (_: pkgs: pkgs.r24) self.packages;
  };
}