Installed libc6-dbg and then ran: LD_LIBRARY_PATH=/usr/lib/debug gdb clara
A backtrace shows some more interesting information: Program received signal SIGSEGV, Segmentation fault. 0x0fd9289c in strlen () from /usr/lib/debug/libc.so.6 (gdb) bt #0 0x0fd9289c in strlen () from /usr/lib/debug/libc.so.6 #1 0x0fd616bc in _IO_vfprintf (s=0x7ffff910, format=0x1 <Address 0x1 out of bounds>, ap=0x7ffffaa0) at vfprintf.c:1526 #2 0x0fd81de8 in _IO_vsnprintf (string=0x7ffff350 "\177ïïmaxlen=0, format=0x1008a1a4 "%s\n", args=0x7ffffaa0) at vsnprintf.c:130 #3 0x100693a0 in to (t=0x100ac880, top=0x100ac624, sz=0x100ac884, fmt=0x1008a1a4 "%s\n") at html.c:1579 #4 0x10002d58 in logmsg (m=0x7ffffb80 "unattended X event 14 (ok)") at clara.c:723 #5 0x10002ff0 in db (m=0x1008c478 "unattended X event %d (ok)") at clara.c:775 #6 0x1002a4e8 in xevents () at event.c:5677 #7 0x1000d2d4 in main (argc=1, argv=0x7ffffd14) at clara.c:5170 micah