{ self, nixpkgs, ... }: let forAllSystems = nixpkgs.lib.genAttrs [ "x86_64-linux" ]; nixpkgsFor = forAllSystems (system: import nixpkgs { inherit system; }); in forAllSystems(system: let pkgs = nixpkgsFor.${system}; in { example = pkgs.callPackage ./example {}; })