{
  description = "slate32 - a Lua app platform for a cheap ESP32 touchscreen";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
  };

  outputs =
    { nixpkgs, ... }:
    let
      systems = [
        "x86_64-linux"
        "aarch64-linux"
      ];
      forAllSystems = nixpkgs.lib.genAttrs systems;
    in
    {
      devShells = forAllSystems (
        system:
        let
          pkgs = import nixpkgs { inherit system; };
        in
        {
          default = pkgs.mkShell {
            packages = with pkgs; [
              platformio-core
              gnumake
              # Host tests run on the same Lua version the firmware vendors.
              lua5_4
              gcc
            ];
            shellHook = ''
              export PLATFORMIO_CORE_DIR="$PWD/.cache/platformio"
            '';
          };
        }
      );
    };
}