anchor.diff:      pixman
       spice-protocol
       usbredir
  +    wayland-protocols
       zlib
  -  ] ++ lib.optionals withPolkit [ polkit acl usbutils ] ;
  +  ] ++ lib.optionals withPolkit [ polkit acl ] ;
   
     PKG_CONFIG_POLKIT_GOBJECT_1_POLICYDIR = "${placeholder "out"}/share/polkit-1/actions";
   
     mesonFlags = [
  -    "-Dcelt051=disabled"
  -    "-Dpulse=disabled" # is deprecated upstream
  +    "-Dusb-acl-helper-dir=${placeholder "out"}/bin"
  +    "-Dusb-ids-path=${hwdata}/share/hwdata/usb.ids"
     ];
   
     meta = with lib; {
  
positive.code: , python3
  , spice-protocol
  , usbredir
  , usbutils
  , vala
  , zlib
  , withPolkit ? true
  }:
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "spice-gtk";
    version = "0.40";
  
    outputs = [ "out" "dev" "devdoc" "man" ];
  
    src = fetchurl {
      url = "https://www.spice-space.org/download/gtk/${pname}-${version}.tar.xz";
      sha256 = "sha256-I/X/f6gLdWR85zzaXq+LMi80Mtu7f286g5Y0YYrbztM=";
    };
  
    postPatch = ''
      # get rid of absolute path to helper in store so we can use a setuid wrapper
      substituteInPlace src/usb-acl-helper.c \
        --replace 'ACL_HELPER_PATH"/' '"'
      # don't try to setcap/suid in a nix builder
      substituteInPlace src/meson.build \
        --replace "meson.add_install_script('../build-aux/setcap-or-suid'," \
        "# meson.add_install_script('../build-aux/setcap-or-suid',"
    '';
  
    nativeBuildInputs = [
  