mjuhasz@desktop:~$ gdb /usr/bin/gtk-window-decorator
GNU gdb (Ubuntu/Linaro 7.4-2012.04-0ubuntu2) 7.4-2012.04
Copyright (C) 2012 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 "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://bugs.launchpad.net/gdb-linaro/>...
Reading symbols from /usr/bin/gtk-window-decorator...(no debugging symbols found)...done.
(gdb) b gdk_x_error
Function "gdk_x_error" not defined.
Make breakpoint pending on future shared library load? (y or [n]) y

Breakpoint 1 (gdk_x_error) pending.
(gdb) run --sync --replace
Starting program: /usr/bin/gtk-window-decorator --sync --replace
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffef1a9700 (LWP 19840)]
[New Thread 0x7fffee9a8700 (LWP 19841)]

Breakpoint 1, gdk_x_error (display=0x650650, error=0x7fffffffd7c0)
    at /build/buildd/gtk+2.0-2.24.10/gdk/x11/gdkmain-x11.c:458
458	/build/buildd/gtk+2.0-2.24.10/gdk/x11/gdkmain-x11.c: No such file or directory.
(gdb) bt
#0  gdk_x_error (display=0x650650, error=0x7fffffffd7c0)
    at /build/buildd/gtk+2.0-2.24.10/gdk/x11/gdkmain-x11.c:458
#1  0x00007ffff76d236f in _XError () from /usr/lib/x86_64-linux-gnu/libX11.so.6
#2  0x00007ffff76cf311 in ?? () from /usr/lib/x86_64-linux-gnu/libX11.so.6
#3  0x00007ffff76d0297 in _XReply () from /usr/lib/x86_64-linux-gnu/libX11.so.6
#4  0x00007ffff76b5ec4 in XGetWindowProperty ()
   from /usr/lib/x86_64-linux-gnu/libX11.so.6
#5  0x0000000000417295 in get_frame_type ()
#6  0x0000000000417548 in ?? ()
#7  0x00007ffff5dd6354 in g_cclosure_marshal_VOID__OBJECTv ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#8  0x00007ffff5dd2eca in ?? ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#9  0x00007ffff5deb741 in g_signal_emit_valist ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#10 0x00007ffff5dec242 in g_signal_emit ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#11 0x00007ffff74694d0 in ?? () from /usr/lib/libwnck-1.so.22
#12 0x00007ffff746a3f4 in ?? () from /usr/lib/libwnck-1.so.22
#13 0x00007ffff5b15d53 in g_main_context_dispatch ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#14 0x00007ffff5b160a0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007ffff5b1649a in g_main_loop_run ()
---Type <return> to continue, or q <return> to quit---
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#16 0x00007ffff6f4d2f7 in IA__gtk_main ()
    at /build/buildd/gtk+2.0-2.24.10/gtk/gtkmain.c:1329
#17 0x000000000040af84 in main ()
(gdb)