anchor.diff:  
     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 ${stdenv.system} (only x86_64 linux is supported)";
  +  src = fetchurl {
  +    url = "${mirror}/${version}/linux/opera-stable_${version}_amd64.deb";
  +    sha256 = "027njqh2as4d0xsnvzamqiplghb8cxqnc19y0vqkvjnsw57v828p";
  +  };
   
     unpackCmd = "${dpkg}/bin/dpkg-deb -x $curSrc .";
   
  
positive.code: let
  
    mirror = https://get.geo.opera.com/pub/opera/desktop;
    version = "46.0.2597.39";
  
    rpath = stdenv.lib.makeLibraryPath [
  
  
negative.code:   meta = {
      homepage = http://www.opera.com;
      description = "Web browser";
      platforms = [ "x86_64-linux" ];
      license = stdenv.lib.licenses.unfree;
    };
  }
  