> On 05/01/2026 17:14 EET Washington Odhiambo via dovecot <[email protected]> > wrote: > > > On Mon, Jan 5, 2026 at 5:55 PM Aki Tuomi <[email protected]> wrote: > > > > > > On 05/01/2026 16:44 EET Washington Odhiambo via dovecot < > > [email protected]> wrote: > > > > > > > > > Can someone please give simple steps to make dovecot to coredump on > > Debian > > > 12? > > > After reading this: > > > https://doc.dovecot.org/2.4.2/developers/debugging.html#coredumps - I am > > > still not able to get it to work. > > > I have been running dovecot from git (yes, I know I shouldn't!) until I > > > updated today and then it would be killed by signal 11. > > > > > > I have so far installed the release versions and all is fine, but I'd > > like > > > to ensure that in the future, I have the coredump working. > > > > > > -- > > > Best regards, > > > Odhiambo WASHINGTON, > > > Nairobi,KE > > > +254 7 3200 0004/+254 7 2274 3223 > > > In an Internet failure case, the #1 suspect is a constant: DNS. > > > "Oh, the cruft.", egrep -v '^$|^.*#' ¯\_(ツ)_/¯ :-) > > > [How to ask smart questions: > > > http://www.catb.org/~esr/faqs/smart-questions.html] > > > Can someone please give simple steps to make dovecot to coredump on > > Debian > > > 12? > > > After reading > > > this: [1] > > https://doc.dovecot.org/2.4.2/developers/debugging.html#coredumps > > > - I am still not able to get it to work. > > > I have been running dovecot from git (yes, I know I shouldn't!) until > > I > > > updated today and then it would be killed by signal 11. > > > I have so far installed the release versions and all is fine, but I'd > > like > > > to ensure that in the future, I have the coredump working. > > > -- > > > > > > I would recommend installing systemd-coredump. Usually the trick with > > getting coredumps is fs.suid_dumpable=2, and if it's login process, setting > > > > service imap-login { > > chroot = > > } > > > > to disable chrooting. systemd-coredump however usually works quite nicely. > > > > Aki > > > > Can you please simplify these steps further? > > Do I have to add fs.suid_dumpable=2 to /etc/sysctl.conf and then do sysctl > -p? > Then what next? > I installed systemd-coredump. Then what next? Reading through the details > was taking all my time. > That's why I opted to install the release versions (manually, actually) > then ask for the simplified steps to get the coredumps. > > If you can help me with that, then I can recompile the git versions and > obtain the coredump. > > What was happening was the usual login failure - for both POP3 and IMAP4. > Authentication was succeeding but dovecot crashed immediately after and > wasn't able to get to the mailbox. > I interacted with the daemons from CLI and both just threw me out. > 'doveadm log errors' showed they were killed by signal 11, but nothing else > much. That's what led me to consider the coredump path. > > > -- > Best regards, > Odhiambo WASHINGTON, > Nairobi,KE > +254 7 3200 0004/+254 7 2274 3223 > In an Internet failure case, the #1 suspect is a constant: DNS. > "Oh, the cruft.", egrep -v '^$|^.*#' ¯\_(ツ)_/¯ :-) > [How to ask smart questions: > http://www.catb.org/~esr/faqs/smart-questions.html] > On Mon, Jan 5, 2026 at 5:55PM Aki Tuomi <[1][email protected]> > wrote: > > > On 05/01/2026 16:44 EET Washington Odhiambo via dovecot > <[2][email protected]> wrote: > > > > > > Can someone please give simple steps to make dovecot to coredump on > Debian > > 12? > > After reading this: > > [3]https://doc.dovecot.org/2.4.2/developers/debugging.html#coredumps - > I am > > still not able to get it to work. > > I have been running dovecot from git (yes, I know I shouldn't!) until > I > > updated today and then it would be killed by signal 11. > > > > I have so far installed the release versions and all is fine, but I'd > like > > to ensure that in the future, I have the coredump working. > > > > -- > > Best regards, > > Odhiambo WASHINGTON, > > Nairobi,KE > > +254 7 3200 0004/+254 7 2274 3223 > > In an Internet failure case, the #1 suspect is a constant: DNS. > > "Oh, the cruft.", egrep -v '^$|^.*#' -\_(Tu)_/- :-) > > [How to ask smart questions: > > [4]http://www.catb.org/~esr/faqs/smart-questions.html] > > Can someone please give simple steps to make dovecot to coredump on > Debian > > 12? > > After reading > > this: > [1][5]https://doc.dovecot.org/2.4.2/developers/debugging.html#coredumps > > - I am still not able to get it to work. > > I have been running dovecot from git (yes, I know I shouldn't!) > until I > > updated today and then it would be killed by signal 11. > > I have so far installed the release versions and all is fine, but > I'd like > > to ensure that in the future, I have the coredump working. > > -- > > I would recommend installing systemd-coredump. Usually the trick with > getting coredumps is fs.suid_dumpable=2, and if it's login process, > setting > > service imap-login { > chroot = > } > > to disable chrooting. systemd-coredump however usually works quite > nicely. > > Aki > > Can you please simplify these steps further? > Do I have to add fs.suid_dumpable=2 to /etc/sysctl.conf and then do sysctl > -p? > Then what next? > I installed systemd-coredump. Then what next? Reading through the details > was taking all my time. > That's why I opted to install the release versions (manually, actually) > then ask for the simplified steps to get the coredumps. > If you can help me with that, then I can recompile the git versions and > obtain the coredump. > What was happening was the usual login failure - for both POP3 and IMAP4. > Authentication was succeeding but dovecot crashed immediately after and > wasn't able to get to the mailbox. > I interacted with the daemons from CLI and both just threw me out. > 'doveadm log errors' showed they were killed by signal 11, but nothing > else much. That's what led me to consider the coredump path. > -- > Best regards, > Odhiambo WASHINGTON, > Nairobi,KE
Did you check coredumpctl? Also make sure sysctl kernel.core_pattern points to systemd-coredump and you have fs.suid_dumpable=2. Aki _______________________________________________ dovecot mailing list -- [email protected] To unsubscribe send an email to [email protected]
