Opera next override

config.nix

# ~/.nixpkgs/config.nix

{
  packageOverrides = pkgs: let
   inherit (builtins) substring stringLength sub;
  in {
       operaNext = pkgs.lib.overrideDerivation pkgs.opera (oldAttrs:
       let s = oldAttrs.preFixup; l=stringLength s; in 
       rec {
         version = "12.00-1450";
         name = "opera-next-${version}";
         src = pkgs.fetchurl {
           url = "http://snapshot.opera.com/unix/next_${version}/${name}.i386.linux.tar.xz";
           sha256 = "1k6qr03i0gnyc3407skizrwv6hdc3h3k3qxa9d6dq70p1xa6rw5k";
         };
         preFixup = "find $out/lib/opera-next" + (substring 20 (sub l 20) s);
         postFixup = ''
           oldRPATH=`patchelf --print-rpath $out/lib/opera-next/opera-next`
           patchelf --set-rpath $oldRPATH:${pkgs.cups}/lib $out/lib/opera-next/opera-next
           '';
       });
}