anchor.diff:  x@{builderDefsPackage
     , qt4, openssl
  -  , xproto, libX11
  +  , xproto, libX11, libXScrnSaver, scrnsaverproto
     , ...}:
   builderDefsPackage
   (a :  
  
positive.code:   buildInputs = map (n: builtins.getAttr n x)
      (builtins.attrNames (builtins.removeAttrs x helperArgNames));
    sourceInfo = rec {
      version="1.0.2";
      baseName="vacuum";
      name="${baseName}-${version}";
      url="http://vacuum-im.googlecode.com/files/${name}-source.tar.gz";
      hash="01ndwxpgr8911f2nfyb6i7avmmlwfikn031q1s60js4lgbqdq3b7";
    };
  in
  rec {
  
negative.code:     echo "Fixing a name collision with a function added in Qt 4.7"
      sed -re 's/qHash[(][a-z ]*QUrl/vacuum_obsolete_&/' -i src/plugins/dataforms/dataforms.cpp
    '') ["minInit" "doUnpack"];
  
    doQMake = a.fullDepEntry (''
      qmake INSTALL_PREFIX=$out -recursive vacuum.pro
  