(gdb) r
Starting program: /media/data/home/tschwinge/tmp/h 
[New Thread 26731.15]

Breakpoint 1, 0x08048236 in main ()
(gdb) info threads
  5 Thread 26731.15  0x080a97fc in mach_msg_trap ()
* 4 Thread 26731.14  0x08048236 in main ()
(gdb) thread 5
[Switching to thread 5 (Thread 26731.15)]#0  0x080a97fc in mach_msg_trap ()
(gdb) bt
#0  0x080a97fc in mach_msg_trap ()
#1  0x080a272e in mach_msg ()
#2  0x080a9934 in mach_msg_server_timeout ()
#3  0x080a99ff in mach_msg_server ()
#4  0x080a327e in _hurd_msgport_receive ()
Cannot access memory at address 0x1012000