_: { perSystem = { config, lib, pkgs, ... }: { devShells.default = pkgs.mkShell { packages = (with pkgs; [ just python314 uv ]) ++ [ pkgs.go_1_27 config.packages.tg ] ++ lib.attrValues config.treefmt.build.programs; shellHook = '' echo "👋 Welcome to the tg devShell!" ''; }; }; }