[Dovecot] Dsync Errors

[Asai]

Greetings,

I've seen something like this in another thread, about a month ago, but we're running into this error pretty frequently when we run dsync backup.

Error: Raw backtrace: /usr/lib64/dovecot/libdovecot.so.0 [0x39ccc5f1c0] -> /usr/lib64/dovecot/libdovecot.so.0(default_fatal_handler+0x35) [0x39ccc5f2a5] -> /usr/lib64/dovecot/libdovecot.so.0 [0x39ccc5ebb3] -> dsync(dsync_brain_mailbox_tree_sync_change+0x41c) [0x42cc0c] -> dsync(dsync_brain_recv_mailbox_tree_deletes+0x10a) [0x42be7a] -> dsync(dsync_brain_run+0x4fc) [0x429cdc] -> dsync [0x42885b] -> dsync [0x4119ff] -> dsync(doveadm_mail_try_run+0x269) [0x411e09] -> dsync(main+0x358) [0x41a2c8] -> /lib64/libc.so.6(__libc_start_main+0xf4) [0x3f4281d994] -> dsync [0x4111c9]

We're running Dovecot 2.2.4 and the dsync command is this:
dsync -u <username> backup maildir:/mnt/backups/<period>/<domain>/<username>

When this happens to a particular users account I delete the backup and let it rebuild, which works for awhile, but then it happens again, and it seems to happen to particular users.

Can you point me in the right direction to start troubleshooting this?

Thanks.

-- 
--Asai