new_contents: try:
      import lxml
      import lxml.etree
      import lxml.html
  except:
      class nothing(object):
          pass
      lxml = nothing()
      lxml.etree = None
      lxml.html = None
  
  import logging
  
  if lxml.html is None:
      logging.warning("Some parts of the OpenHatch site may fail because the lxml"
                      " library is not installed. Look in README.mkd for"
                      " information about lxml.")
  
subject: Move lxml into separate depends file