{
# vim: set et,sw=4
  description = "Flake utils demo";

  inputs.flake-utils.url = "github:numtide/flake-utils";

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let pkgs = nixpkgs.legacyPackages.${system}; in
      {
        packages = rec {
          performous-composer = pkgs.libsForQt5.callPackage ./performous-composer.nix {};
          open-simh = pkgs.stdenv.mkDerivation {
            pname = "open-simh";
            version = "4.0.0";
            src = pkgs.fetchFromGitHub {
              owner = "open-simh";
              repo = "simh";
              rev = "d4f85d01bdf7301d5f7a2c4e51c3a84024561b26";
              sha256 = "sha256-kjLX8JeG7nPNz7KLheQCKz8kKA1xPn0CpRg+N336r1w=";
            };
            postPatch = ''
              ${pkgs.ed}/bin/ed BESM6/CMakeLists.txt <<'_EOF_'
              /foreach (fdir \''${cand_fontdirs})/
              i
              string(REPLACE " " ";" extra_cand_fontdirs "$ENV{buildInputs} $ENV{nativeBuildInputs}")
              foreach(extra_fdir IN LISTS extra_cand_fontdirs)
                  list(APPEND cand_fontdirs ''${extra_fdir})
              endforeach()
              .
              wq
              _EOF_'';
            buildInputs = with pkgs; [
              libpcap
              vde2
              pcre
              libedit
              SDL2 SDL2_ttf
              libpng
              zlib
              freetype
              pkg-config
              dejavu_fonts
            ];
            nativeBuildInputs = [ pkgs.cmake pkgs.ninja ];
          };
        };
        apps = rec {
          hello = flake-utils.lib.mkApp { drv = self.packages.${system}.hello; };
          default = hello;
        };
      }
    );
}