new_contents: """Utility to retrieve the buildout dir from bzr.
  
  This has the advantage over the Bazaar source step to be inconditionnal,
  and always retrieve the head of the wanted branch.
  
  This may become useless once multi-repo is there and we use it.
  """
  
  import os
  from subprocess import check_call
  from argparse import ArgumentParser
  
  parser = ArgumentParser()
  parser.add_argument('url')
  
  arguments = parser.parse_args()
  url = arguments.url
  
  if not os.path.exists(os.path.join('.bzr')):
      check_call(['bzr', 'init'])
  
  check_call(['bzr', 'pull', url])
  
subject: support buildouts provided by bzr (was parlty committed, sorry)