First, make sure you’ve installed the debugging symbols for GNUstep, SOGo and SOPE. On RHEL-based distributions, debugging symbols will be located in packages with the “debuginfo” suffix, while on Debian-based distributions, the suffix is “dbg”.
So, on RHEL-based distributions, proceed with the following command:
yum install sogo-debuginfo sope49-debuginfo gnustep-base-debuginfo
On Debian-based distributions, proceed with the following command:
apt-get install libgnustep-base*-dbg sogo-dbg sope4.9-dbg
On older Debians (Squeeze), the gdb version shipped with the system won’t work with PIE executables. To workaround this problem, a newer gdb must be installed from the backports.
Add this line to /etc/apt/sources.list (or add a new file with the “.list” extension to /etc/apt/sources.list.d/):
deb http://backports.debian.org/debian-backports squeeze-backports main
Run apt-get update
- Install the package
apt-get -t squeeze-backports install "gdb"
If you’re only interested in debugging SOGo, make sure it’s first stopped and no “sogod” process is running.
Then, change to the SOGo user and launch SOGo inside gdb:
% su -s /bin/bash - sogo
% gdb --args /usr/sbin/sogod -WOUseWatchDog NO -WONoDetach YES -WOPort 20000 -WOWorkersCount 1 -WOLogFile - -WOPidFile /tmp/sogo.pid
Launch the application using the “run” command (or “r”). This will start SOGo using a single process inside gdb.
Once SOGo is launched, hit Control-C and set breakpoints, like this:
(gdb) b [NSException raise]
Breakpoint 1 at 0x7ffff5241d90: file NSException.m, line 955.
(gdb) b abort
Breakpoint 2 at 0x7ffff5352f50: abort. (2 locations)
Resume’s SOGo state, putting it back into a running one:
When the application is about to crash, your breakpoints should be raised:
Breakpoint 1, -[NSException raise] (self=0x55555611fe20, _cmd=0x7ffff56f5f00) at NSException.m:955
At this point, you can produce a back trace using the “bt” command:
#0 -[NSException raise] (self=0x55555611fe20, _cmd=0x7ffff56f5f00) at NSException.m:955
#1 0x00007ffff5242231 in +[NSException raise:format:] (self=0x7ffff56f6080, _cmd=<optimized out>, name=0x7ffff56f6220,
format=0x7ffff56c57f0) at NSException.m:835
#2 0x00007ffff51b8e89 in characterAtIndex_c (index=306, self=<optimized out>) at GSString.m:1199
#3 -[GSMutableString characterAtIndex:] (self=0x555555878630, _cmd=<optimized out>, index=<optimized out>) at GSString.m:3797
#4 0x00007ffff7b73185 in -[NSString(SOGoURLExtension) _rangeOfURLInRange:] (self=0x555555878630, _cmd=0x7ffff7dc9e00, refRange=...)
#5 0x00007ffff7b73732 in -[NSString(SOGoURLExtension) _handleURLs:textToMatch:prefix:inRanges:] (self=0x55555610bbf0, _cmd=0x7ffff7dc9ec0,
selfCopy=0x555555878630, match=0x7ffff7dc9240, prefix=0x7ffff7dc9260, ranges=0x555555878b70) at NSString+Utilities.m:202
#6 0x00007ffff7b73c49 in -[NSString(SOGoURLExtension) stringByDetectingURLs] (self=0x55555610bbf0, _cmd=0x7fffea5b6c80)
#7 0x00007fffea3a8537 in -[UIxMailPartTextViewer flatContentAsString] (self=0x555556056070, _cmd=0x5555562d6e00)
You can also attach to a running sogod process using gdb. For example, if a sogod process is consuming 100% and its PID is 1234, you can attach to it using “gdb -p 1234”. At this point, you can also produce back traces (“bt” or “bt full”), put the process back in the running state (“c”) or interrupt it (Control-C).
Next thing is to file a detailed bug on http://sogo.nu/bugs.