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