Mailman 2.2+ error when performing News Gateway sync

Symptoms

Mailman has the ability to sync with external News applications via the NNTP protocol.  Since the upgrade to Mailman 2.2.0, the NNTP sync gives the following error:

Traceback (most recent call last):
  File "/usr/local/cpanel/3rdparty/mailman/cron/./gate_news", line 286, in <module>
    main()
  File "/usr/local/cpanel/3rdparty/mailman/cron/./gate_news", line 266, in main
    process_lists(lock)
  File "/usr/local/cpanel/3rdparty/mailman/cron/./gate_news", line 243, in process_lists
    poll_newsgroup(mlist, conn, start, last+1, glock)
  File "/usr/local/cpanel/3rdparty/mailman/cron/./gate_news", line 126, in poll_newsgroup
    headers = conn.head(repr(num))[3]
IndexError: tuple index out of range

Description

The error occurs as the data received from the News Gateway is not being parsed correctly by the updated Mailman software.

We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-46537. Follow this article to receive an email notification when a solution is published in the product. 

Workaround

There is currently no workaround.