doveadm backup abort in imapc-client.c

[Evan Klitzke]

I am using Dovecot 2.2.36 and I am trying to use doveadm backup to 
migrate email from Gmail to Dovecot. When I run doveadm backup, it goes 
for a while and then eventually hits an assertion error (I've tried this 
a few times now and it happens reliably).

The assertion failure looks like this:

dsync(evan at eklitzke.org): Panic: file imapc-client.c: line 179 
(imapc_client_run_pre): assertion failed: (client->ioloop == NULL)

The last few lines of log output before the crash look like this: 
https://gist.github.com/eklitzke/9a0dd77c44a6ee33e812f85d5773c24c

The GDB backtrace when the program panics looks like this: 
https://gist.github.com/eklitzke/6b311474b08b546c462e0444c5cf479b

The output of "dovecot --version" prints "2.2.36 (1f10bfa63)" and I'm 
using the version provided by Fedora's dovecot-2.2.36-1.fc28.src.rpm 
package.

Is there any other information I can provide to assist in debugging? I 
could provide a core dump provided there was a way to scrub my IMAP 
credentials.

--
Evan Klitzke                      pgp: 0x157EFCACBC648422
e: evan at eklitzke.org              w: https://eklitzke.org