anchor.diff:    };
   
     pango = attrs: {
  -  nativeBuildInputs = [ pkgconfig ];
  +    nativeBuildInputs = [ pkgconfig ];
       buildInputs = [ gtk2 xorg.libXdmcp pcre xorg.libpthreadstubs ];
     };
   
  
positive.code:   };
  
    rmagick = attrs: {
    nativeBuildInputs = [ pkgconfig ];
      buildInputs = [ imagemagick which ];
    };
  
  
negative.code:     '';
    };
  
    fog-dnsimple = attrs: {
      postInstall = ''
        cd $(cat $out/nix-support/gem-meta/install-path)
        rm {$out/bin,bin,../../bin}/{setup,console}
      '';
    };
  
    redis-rack = attrs: {
      dontBuild = false;
      preBuild = ''
        exec 3>&1
        output="$(gem build $gemspec | tee >(cat - >&3))"
        exec 3>&-
        sed -i 's!"rake".freeze!!' $gemspec
      '';
    };
  
    ffi-rzmq-core = attrs: {
      postInstall = ''
        installPath=$(cat $out/nix-support/gem-meta/install-path)
        sed -i $installPath/lib/ffi-rzmq-core/libzmq.rb -e 's@inside_gem =.*@inside_gem = "${zeromq}/lib"@'
      '';
    };
  
    mini_magick = attrs: {
      postInstall = ''
        installPath=$(cat $out/nix-support/gem-meta/install-path)
        echo -e "\nENV['PATH'] += ':${graphicsmagick}/bin'\n" >> $installPath/lib/mini_magick/configuration.rb
      '';
    };
  
    do_sqlite3 = attrs: {
      buildInputs = [ sqlite ];
    };
  