anchor.diff:      gdk_pixbuf.out
       glib.out
       gnome2.GConf.out
  -    gtk2.out
  +    gtk3.out
       libX11.out
       libXScrnSaver.out
       libXcomposite.out
  
positive.code: let
  
    mirror = https://get.geo.opera.com/pub/opera/desktop;
    version = "45.0.2552.898";
  
    rpath = stdenv.lib.makeLibraryPath [
  
  
negative.code:   name = "opera-${version}";
  
    src =
      #if stdenv.system == "i686-linux" then
      #  fetchurl {
      #    url = "${mirror}/${version}/linux/opera-stable_${version}_i386.deb";
      #    sha256 = "...";
      #  }
      #else 
      if stdenv.system == "x86_64-linux" then
        fetchurl {
          url = "${mirror}/${version}/linux/opera-stable_${version}_amd64.deb";
          sha256 = "1ladvqilm5rr222wjybvribnyii2l0p8jbsd10xr06wps63g1kia";
        }
      else throw "Opera is not supported on ${stdenv.system} (only x86_64 linux is supported)";
  
    unpackCmd = "${dpkg}/bin/dpkg-deb -x $curSrc .";
  
  