anchor.diff:      sha256 = "1gczv8hn3wqci86css3mhzrppp3z8vppxw25l08j589k6bvz7x1w";
     };
   
  -  nativeBuildInputs = [ python python.pkgs.sphinx pkgconfig flex bison ];
  +  nativeBuildInputs = [ python python.pkgs.sphinx pkgconfig flex bison ]
  +    ++ optionals gtkSupport [ wrapGAppsHook ];
     buildInputs =
       [ zlib glib ncurses perl pixman
         vde2 texinfo makeWrapper lzo snappy
  
positive.code:     ++ optional smbdSupport "--smbd=${samba}/bin/smbd";
  
    doCheck = false; # tries to access /dev
  
    postFixup =
      ''
        # copy qemu-ga (guest agent) to separate output
        mkdir -p $ga/bin
        cp $out/bin/qemu-ga $ga/bin/
      '';
  
    # Add a ‘qemu-kvm’ wrapper for compatibility/convenience.
  
negative.code: , seccompSupport ? stdenv.isLinux, libseccomp
  , pulseSupport ? !stdenv.isDarwin, libpulseaudio
  , sdlSupport ? !stdenv.isDarwin, SDL2
  , gtkSupport ? !stdenv.isDarwin && !xenSupport, gtk3, gettext, vte, wrapGAppsHook
  , vncSupport ? true, libjpeg, libpng
  , smartcardSupport ? true, libcacard
  , spiceSupport ? !stdenv.isDarwin, spice, spice-protocol
  