{ inputs = { nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable"; flake-utils.url = "github:numtide/flake-utils"; }; outputs = { self, nixpkgs, flake-utils, ... }: flake-utils.lib.eachDefaultSystem (system: let pkgs = import nixpkgs { inherit system; }; in with pkgs; { devShells.default = mkShell { buildInputs = [ rustup ]; }; } ); }