dovecot -2.2.24 on Fedora 31

[Aki Tuomi]

On 12.11.2019 9.49, Frank Elsner wrote:
> On Tue, 12 Nov 2019 09:22:56 +0200 Aki Tuomi via dovecot wrote:
>> Hi!
>>
>> Can you try follow this guide to get a core dump
>>
>> https://www.dovecot.org/bugreport-mail
>>
>> then provide
>>
>>
>> gdb /usr/lib/dovecot/auth /path/to/core
>>
>> bt full
> Sorry, I'm not familiar with gdb and can only provide this
>
> # gdb /usr/local/dovecot//libexec/dovecot/auth
> GNU gdb (GDB) Fedora 8.3.50.20190824-24.fc31
> Copyright (C) 2019 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.
> Type "show copying" and "show warranty" for details.
> This GDB was configured as "x86_64-redhat-linux-gnu".
> Type "show configuration" for configuration details.
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>.
> Find the GDB manual and other documentation resources online at:
>     <http://www.gnu.org/software/gdb/documentation/>.
>
> For help, type "help".
> Type "apropos word" to search for commands related to "word"...
> Reading symbols from /usr/local/dovecot//libexec/dovecot/auth...
> (gdb) bt full
> No stack.
> (gdb) r
> Starting program: /usr/local/dovecot/libexec/dovecot/auth 
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib64/libthread_db.so.1".
>
> Program received signal SIGSEGV, Segmentation fault.
> __strcmp_ssse3 () at ../sysdeps/x86_64/multiarch/../strcmp.S:173
> 173             movlpd  (%rdi), %xmm1


Well, you need to get a core file first, which is documented in the page
I linked.

Once you have a core file, somewhere, you should use

gdb  /usr/lib/dovecot/auth /var/core/1234

and then try bt full.

There is no point using gdb without core file in this particular case.

If you are using systemd, you can do

systemctl edit dovecot

[Service]

LimitCORE=unlimited


Aki