anchor.diff:  , openssl, libpulseaudio, pixman, gobjectIntrospection, libjpeg_turbo, zlib
   , cyrus_sasl, python2Packages, autoreconfHook, usbredir, libsoup
   , withPolkit ? true, polkit, acl, usbutils
  -, vala, gtk3, epoxy, libdrm, gst_all_1, phodav }:
  +, vala, gtk3, epoxy, libdrm, gst_all_1, phodav, opusfile }:
   
   # If this package is built with polkit support (withPolkit=true),
   # usb redirection reqires spice-client-glib-usb-acl-helper to run setuid root.
  
positive.code:     "--with-gtk3"
      "--enable-introspection"
      "--enable-vala"
    ];
  
    dontDisableStatic = true; # Needed by the coroutine test
  
negative.code: 
    buildInputs = [
      spice-protocol celt_0_5_1 openssl libpulseaudio gst_all_1.gst-plugins-base pixman
      libjpeg_turbo zlib cyrus_sasl python pygtk usbredir gtk3 epoxy libdrm phodav opusfile
    ] ++ optionals withPolkit [ polkit acl usbutils ] ;
  
    nativeBuildInputs = [ pkgconfig gettext libsoup autoreconfHook vala gobjectIntrospection ];
  