flake-utils/example/flake.nix

{
  description = "Flake utils demo";
  edition = 201909;

  inputs.utils = {
    uri = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, utils }:
    utils.lib.eachDefaultSystem (system:
      let pkgs = nixpkgs.legacyPackages.${system}; in
      rec {
        packages.hello = pkgs.hello;
        defaultPackage = packages.hello;
        apps.hello = utils.lib.mkApp { drv = packages.hello; };
        defaultApp = apps.hello;
      }
    );
}