anchor.diff:      "WideLM" # depends on proprietary cudatoolkit
       "x_ent" # requires opencpu
       "xergm" # requires nlopt
  -    "xml2" # build is broken
       "ZeligMultilevel" # Requires Nlopt
       "zetadiv" # requires nlopt
       "zoib" # tarball is invalid on server
  
positive.code: 
    otherOverrides = old: new: {
      xml2 = old.xml2.overrideDerivation (attrs: {
        preConfigure = ''
          export LIBXML_INCDIR=${pkgs.libxml2}/include/libxml2
          export LIBXML_LIBDIR=${pkgs.libxml2}/lib
        '';
      });
  
      curl = old.curl.overrideDerivation (attrs: {
  
negative.code:     VBmix = [ pkgs.gsl pkgs.fftw pkgs.qt4 ];
      WhopGenome = [ pkgs.zlib ];
      XBRL = [ pkgs.zlib pkgs.libxml2 ];
      xml2 = [ pkgs.libxml2 ];
      XML = [ pkgs.libtool pkgs.libxml2 pkgs.xmlsec pkgs.libxslt ];
    };
  
  