Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1223178544 (LWP 12712)]
0xb7214d8b in strlen () from /lib/libc.so.6
(gdb) thread apply all bt

Thread 3 (Thread -1235965040 (LWP 12721)):
#0  0xb7f71410 in ?? ()
#1  0xb654a388 in ?? ()
#2  0x00000000 in ?? ()

Thread 2 (Thread -1227138160 (LWP 12720)):
#0  0xb7f71410 in ?? ()
#1  0xb6db5348 in ?? ()
#2  0x00000001 in ?? ()
#3  0xb73f8556 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#4  0xb7456cdf in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
Previous frame inner to this frame (corrupt stack?)

Thread 1 (Thread -1223178544 (LWP 12712)):
#0  0xb7214d8b in strlen () from /lib/libc.so.6
#1  0xb71e90f1 in vfprintf () from /lib/libc.so.6
#2  0x083556e9 in ?? ()
#3  0x00000001 in ?? ()
#4  0x00000002 in ?? ()
#5  0xb71e4e70 in _IO_helper_overflow () from /lib/libc.so.6