let
  sources = import ./nix/sources.nix;
  pkgs = import sources.nixpkgs {
    overlays = [
      (_: _: { inherit sources; })
      (import ./overlay.nix)
    ];
  };
in
with pkgs;

stdenv.mkDerivation {
  name = "nix-cpp-demo";
  nativeBuildInputs = [ cmake pkgconfig ];
  src = pkgs.lib.cleanSource ./.;

  # tell Cmake location of all headers
  cmakeFlags = [
    "-DEXTERNAL_INCLUDE_DIRECTORIES=${lib.strings.makeSearchPathOutput "dev" "include" libosmium.buildInputs}"
  ];

  buildInputs = lib.lists.concatLists [
    # We want to check if dependencies exist using find_package
    [
      libosmium.buildInputs
    ]
    # dependencies
    [
      libosmium
    ]
  ];

  installPhase = ''
    mkdir -p $out/bin
    cp bin/hello-world $out/bin
  '';
}