On 14. Jan 2019, at 10:33, Joan Moreau via dovecot <dovecot@dovecot.org> wrote:

Difficult to figure out without a coredump + gdb

I have also battled quite a lot to make sure dovecot can core dump on my Archlinux servers.

I remember that the key point was putting fs.suid_dumpable=2 in /etc/sysctl.d/ conf files, LimitCORE=infinity in /etc/systemd/system/multi-user.target.wants/dovecot.service,  and rebooting the server.

My own coredumps are on /var/lib/systemd/coredump/