anchor.diff:  
           nodePackages.jshint
   
  -        python27Packages.jinja2
  +#        python27Packages.jinja2
           vimHugeX
  +        lessc  # searx
  +
  +        python27Packages.pyflakes
  +        python27Packages.pep8
         ];
         pathsToLink = [ "/" ];
         ignoreCollisions = true;
  
positive.code:         postgresql
          pycrypto
          python27Full
          python27Packages.ipython
          python27Packages.pyyaml
  #        python27Packages.readline
  #        python27Packages.sqlite3
  
negative.code:         stdenv
          wget
          zlib
          w3m
          poppler
  #        rubyLibs.docsplit
  #        python27Packages.ipdb
  #        docutils
  #        python27Packages.pygments
          vimprobable2
  #        python27Packages.cssselect
          gettext
          python27Packages.libarchive
  #        python27.modules.curses
  