pgquiles@pravetz:~/kde/bin$ gdb ./kolf -d /home/pgquiles/downloads/qt4.3/qt4-x11-4.3.0/src/gui
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This GDB was configured as "i486-linux-gnu"...
Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
(gdb) b qt_x_errhandler
Function "qt_x_errhandler" not defined.
Make breakpoint pending on future shared library load? (y or [n]) y
Breakpoint 1 (qt_x_errhandler) pending.
(gdb) run --sync -dograb
Starting program: /home/pgquiles/kde/bin/kolf --sync -dograb
[Thread debugging using libthread_db enabled]
[New Thread -1254459696 (LWP 18901)]
Breakpoint 2 at 0xb689a819: file kernel/qapplication_x11.cpp, line 423.
Pending breakpoint "qt_x_errhandler" resolved
[Switching to Thread -1254459696 (LWP 18901)]

Breakpoint 2, qt_x_errhandler (dpy=0x805fb88, err=0xbfb938a8) at kernel/qapplication_x11.cpp:423
423     static int qt_x_errhandler(Display *dpy, XErrorEvent *err)
(gdb) n
425         switch (err->error_code) {
(gdb) n
474             if (err->request_code == X11->xinput_major
(gdb) n
483         XGetErrorText( dpy, err->error_code, errstr, 256 );
(gdb) n
486         qsnprintf(buffer, 256, "%d", err->request_code);
(gdb) n
487         XGetErrorDatabaseText(dpy, "XRequest", buffer, "", request_str, 256);
(gdb) n
488         if (err->request_code < 128) {
(gdb) n
496                       err->resourceid );
(gdb) n
X Error: BadValue (integer parameter out of range for operation) 2
  Major opcode: 78 (X_CreateColormap)
  Resource id:  0x28a
530         return 0;
(gdb) bt
#0  qt_x_errhandler (dpy=0x805fb88, err=0xbfb938a8) at kernel/qapplication_x11.cpp:530
#1  0xb6f30c4a in _XError () from /usr/lib/libX11.so.6
#2  0xb6f32714 in _XReply () from /usr/lib/libX11.so.6
#3  0xb6f2c5ca in XSync () from /usr/lib/libX11.so.6
#4  0xb6f2c745 in ?? () from /usr/lib/libX11.so.6
#5  0x0805fb88 in ?? ()
#6  0x00000000 in ?? ()
(gdb)