{ description = "A very basic flake"; inputs = { nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable"; fenix.url = "github:nix-community/fenix"; flake-utils.url = "github:numtide/flake-utils"; }; outputs = { nixpkgs, fenix, flake-utils, ... }: flake-utils.lib.eachDefaultSystem ( system: let pkgs = import nixpkgs { inherit system; }; toolchain = fenix.packages.${system}.stable.toolchain; in { devShells.default = pkgs.mkShell { packages = [ toolchain ]; }; } ); }