{
  description = "ESP32-D0WD-V3 (esp32-hal) Rust dev flake";

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

  outputs = { self, nixpkgs }: let
    system = "x86_64-linux";
    pkgs = import nixpkgs { inherit system; };
  in {
    devShells.${system}.default = pkgs.mkShell {
      packages = with pkgs; [
        llvm
        cmake
        ninja
        python3
        pkg-config
        git
        curl
        wget
        unzip
        gcc
        gnumake
        rustup
        cargo-espflash
        espup
	mosquitto
      ];

shellHook = ''
  echo ">>> ESP32 DevShell (esp-hal only)"

  if [ ! -d "$HOME/.espup" ]; then
    echo "Running espup install..."
    espup install
  fi

  # Activate Xtensa Rust toolchain
  export RUSTUP_TOOLCHAIN=esp
  export PATH=$HOME/.rustup/toolchains/esp/bin:$PATH

  # Add GCC/binutils path for xtensa-esp32-elf-gcc
  export PATH=$HOME/.rustup/toolchains/esp/xtensa-esp-elf/esp-14.2.0_20240906/xtensa-esp-elf/bin:$PATH

  echo "Xtensa Rust toolchain ready."
  rustc --version
  which xtensa-esp32-elf-gcc || echo "⚠️ xtensa-esp32-elf-gcc not found in PATH"
'';
    };
  };
}