You can clone with
HTTPS or Subversion.
See the detailed error here: http://kevin.deldycke.com/2010/08/maildir-deduplication-script-python/comment-page-1/#comment-8768
This issue is 2 years old and maildir-deduplicate.py dramatically changed since then. This script also moved to its own repository, so if this issue is still current, please open a new ticket over there.