Breakpoint 1, 0x0000003b500aa260 in _exit () from /lib64/libc.so.6
(gdb) bt
#0  0x0000003b500aa260 in _exit () from /lib64/libc.so.6
#1  0x0000003b50036f12 in exit () from /lib64/libc.so.6
#2  0x0000003423c65cff in ?? () from /usr/lib64/libgdk-x11-3.0.so.0
#3  0x0000003b53c46da4 in _XError () from /usr/lib64/libX11.so.6
#4  0x0000003b53c4d277 in ?? () from /usr/lib64/libX11.so.6
#5  0x0000003b53c4d983 in _XReply () from /usr/lib64/libX11.so.6
#6  0x0000003b584051bc in XRRGetOutputProperty ()
   from /usr/lib64/libXrandr.so.2
#7  0x000000000041c25a in gpm_brightness_output_get_internal (brightness=
    0x6d5180, output=81, cur=0x7fffffffd644) at gpm-brightness.c:178
#8  0x000000000041c780 in gpm_brightness_output_get_percentage (brightness=
    0x6d5180, op=<value optimized out>) at gpm-brightness.c:323
#9  gpm_brightness_foreach_resource (brightness=0x6d5180, 
    op=<value optimized out>) at gpm-brightness.c:489
#10 gpm_brightness_foreach_screen (brightness=0x6d5180, 
    op=<value optimized out>) at gpm-brightness.c:526
#11 0x000000000041ce9a in gpm_brightness_get (brightness=0x6d5180, percentage=
    0x7fffffffd6d4) at gpm-brightness.c:633
#12 0x000000000040c349 in gpm_backlight_brightness_evaluate_and_set (backlight=
    0x665a80, interactive=0) at gpm-backlight.c:342
#13 0x0000003b52430915 in g_type_create_instance ()
   from /lib64/libgobject-2.0.so.0
#14 0x0000003b5241369c in ?? () from /lib64/libgobject-2.0.so.0
---Type <return> to continue, or q <return> to quit---fram 7
#15 0x0000003b5241496a in g_object_newv () from /lib64/libgobject-2.0.so.0
#16 0x0000003b5241519c in g_object_new () from /lib64/libgobject-2.0.so.0
#17 0x000000000041033b in gpm_manager_init (manager=0x673440)
    at gpm-manager.c:1985
#18 0x0000003b52430915 in g_type_create_instance ()
   from /lib64/libgobject-2.0.so.0
#19 0x0000003b5241369c in ?? () from /lib64/libgobject-2.0.so.0
#20 0x0000003b5241496a in g_object_newv () from /lib64/libgobject-2.0.so.0
#21 0x0000003b5241519c in g_object_new () from /lib64/libgobject-2.0.so.0
#22 0x000000000040fa82 in gpm_manager_new () at gpm-manager.c:2104
#23 0x000000000040f5ec in main (argc=1, argv=0x7fffffffe208) at gpm-main.c:248
(gdb) fram 7
#7  0x000000000041c25a in gpm_brightness_output_get_internal (brightness=
    0x6d5180, output=81, cur=0x7fffffffd644) at gpm-brightness.c:178
178		if (XRRGetOutputProperty (brightness->priv->dpy, output, brightness->priv->backlight,
(gdb) list
173		int actual_format;
174		gboolean ret = FALSE;
175	
176		g_return_val_if_fail (GPM_IS_BRIGHTNESS (brightness), FALSE);
177	
178		if (XRRGetOutputProperty (brightness->priv->dpy, output, brightness->priv->backlight,
179					  0, 4, False, False, None,
180					  &actual_type, &actual_format,
181					  &nitems, &bytes_after, ((unsigned char **)&prop)) != Success) {
182			egg_debug ("failed to get property");
(gdb) p *brightness
$1 = {parent = {g_type_instance = {g_class = 0x69ac70}, ref_count = 1, qdata = 
    0x7fffec0018a0}, priv = 0x6d51a0}
(gdb) p *(brightness->priv)
$2 = {has_changed_events = 0, cache_trusted = 0, cache_percentage = 0, 
  last_set_hw = 0, backlight = 0, dpy = 0x653e00, root_window = 0x669030, 
  shared_value = 0, has_extension = 0, has_randr13 = 1, hw_changed = 0, 
  resources = 0x7fffec001900, extension_levels = 10, extension_current = 0}
(gdb) p *(brightness->priv->dpy)
$3 = <incomplete type>
(gdb) p *(brightness->priv->backlight)
Cannot access memory at address 0x0