{ description = "A Nix-flake-based Ruby development environment"; inputs = { flake-utils.url = "github:numtide/flake-utils"; nixpkgs.url = "github:NixOS/nixpkgs"; }; outputs = { self , flake-utils , nixpkgs }: flake-utils.lib.eachDefaultSystem (system: let overlays = [ (self: super: { ruby = super.ruby_3_1; }) ]; pkgs = import nixpkgs { inherit overlays system; }; in { devShells.default = pkgs.mkShell { packages = with pkgs; [ ruby ]; shellHook = '' ${pkgs.ruby}/bin/ruby --version ''; }; }); }