KeyError during IMAP to IMAP sync of deleted msgs

[Dan Christensen]

Dan Christensen <jdc at uwo.ca> writes:

> I get a very similar backtrace whenever I try to sync a large number of
> new messages in a local IMAP folder to a remote IMAP folder.  (Both
> servers running dovecot under Ubuntu.)  It's 100% repeatable, and like
> Tony, offlineimap makes progress so if I run it repeatedly it eventually
> finishes.  The error typically occurs after several hundred messages
> have been successfully copied.  Since I've converting some large folders
> from another format to imap, I've having to run offlineimap dozens of
> times per folder.

Unfortunately, the problem is more serious than having to restart
offlineimap.  After the sync finally completed, one message was missing
from the local IMAP folder, and 55 messages were duplicated!

When syncing another large folder, I didn't notice any missing or
duplicate messages, but offlineimap did lose all the
read/replied/flagged flags, so I had to delete the imap folder and
redo the conversion.

> Any information I can provide to help debug this further?

Given that the problem seems to cause corruption, I think it's worth
looking into further.

Dan