{ description = "COSMIC Development Environment"; 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 inherit (nixpkgs.lib) optional; pkgs = import nixpkgs {inherit system;}; fhs = pkgs.buildFHSUserEnv { name = "COSMIC"; targetPkgs = pkgs: (with pkgs; [ # There is a lot here, because I am not sure about your system. :) xorg.libX11 xorg.libXext xorg.libxcb udev #runScript = "bash -c ./pico8"; }; in { devShell = pkgs.mkShell { buildInputs = with pkgs; [ fhs ]; shellHook = '' if [ -e pico8 ] then tput setaf 2; echo "Pico-8 binary present. Type 'pico8' to get started."; tput sgr0; else tput setaf 3; echo "No Pico-8 binary present. Please download it."; tput sgr0; echo "You can purchase it here:" tput setaf 2; echo "https://www.lexaloffle.com/pico-8.php"; tput sgr0; fi ''; }; }); }