I can reproduce this by simply issuing:
doveadm reload
GNU gdb (GDB) 7.0.1-debian
Copyright (C) 2009 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 "i486-linux-gnu".
For bug reporting instructions, please see:
http://www.gnu.org/software/gdb/bugs/...
Reading symbols from /usr/dovecot-2/libexec/dovecot/auth...done.
Reading symbols from /usr/dovecot-2/lib/dovecot/libdovecot.so.0...done.
Loaded symbols for /usr/dovecot-2/lib/dovecot/libdovecot.so.0
Reading symbols from /lib/i686/cmov/libcrypt.so.1...Reading symbols from /usr/lib/debug/lib/i686/cmov/libcrypt-2.11.2.so...done.
(no debugging symbols found)...done.
Loaded symbols for /lib/i686/cmov/libcrypt.so.1
Reading symbols from /lib/libpam.so.0...(no debugging symbols found)...done.
Loaded symbols for /lib/libpam.so.0
Reading symbols from /lib/i686/cmov/libdl.so.2...Reading symbols from /usr/lib/debug/lib/i686/cmov/libdl-2.11.2.so...done.
(no debugging symbols found)...done.
Loaded symbols for /lib/i686/cmov/libdl.so.2
Reading symbols from /lib/i686/cmov/libc.so.6...Reading symbols from /usr/lib/debug/lib/i686/cmov/libc-2.11.2.so...done.
(no debugging symbols found)...done.
Loaded symbols for /lib/i686/cmov/libc.so.6
Reading symbols from /lib/i686/cmov/librt.so.1...Reading symbols from /usr/lib/debug/lib/i686/cmov/librt-2.11.2.so...done.
(no debugging symbols found)...done.
Loaded symbols for /lib/i686/cmov/librt.so.1
Reading symbols from /lib/ld-linux.so.2...Reading symbols from /usr/lib/debug/lib/ld-2.11.2.so...done.
(no debugging symbols found)...done.
Loaded symbols for /lib/ld-linux.so.2
Reading symbols from /lib/i686/cmov/libpthread.so.0...Reading symbols from /usr/lib/debug/lib/i686/cmov/libpthread-2.11.2.so...done.
(no debugging symbols found)...done.
Loaded symbols for /lib/i686/cmov/libpthread.so.0
Reading symbols from /lib/libgcc_s.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib/libgcc_s.so.1
Core was generated by `dovecot/auth'.
Program terminated with signal 6, Aborted.
#0 0xb772e430 in __kernel_vsyscall ()
#0 0xb772e430 in __kernel_vsyscall ()
No symbol table info available.
#1 0xb7556751 in *__GI_raise (sig=6)
at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
resultvar = <value optimized out>
pid = -1217994764
selftid = 22112
#2 0xb7559b82 in *__GI_abort () at abort.c:92
act = {__sigaction_handler = {sa_handler = 0xbfdc3ed0,
sa_sigaction = 0xbfdc3ed0}, sa_mask = {__val = {3077757632,
3218882212, 3077800674, 3218882196, 3077323828, 3218882184,
3077880404, 0, 3075510304, 1, 0, 1, 3077757192, 3218882108,
3218882104, 3077532336, 3077526747, 3077739624, 3218882188,
166684304, 0, 3218882256, 3218882184, 3218882196, 3077532029,
3077757192, 0, 725, 3218882216, 3077348830, 3218882188, 10}},
sa_flags = -1076084988, sa_restorer = 0xb772a70c
-- Ralf Hildebrandt Geschäftsbereich IT | Abteilung Netzwerk Charité - Universitätsmedizin Berlin Campus Benjamin Franklin Hindenburgdamm 30 | D-12203 Berlin Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962 ralf.hildebrandt@charite.de | http://www.charite.de