$ gdb /usr/lib/notification-daemon/notification-daemon 
GNU gdb (GDB) 7.6.2 (Debian 7.6.2-1.1+b1)
Copyright (C) 2013 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://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/lib/notification-daemon/notification-daemon...(no debugging symbols found)...done.
(gdb) run
Starting program: /usr/lib/notification-daemon/notification-daemon 
warning: no loadable sections found in added symbol-file system-supplied DSO at 0x7ffff7ffa000
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffebd10700 (LWP 2447)]
[New Thread 0x7fffeac55700 (LWP 2448)]

(notification-daemon:2443): Gtk-WARNING **: gtk_widget_size_allocate(): attempt to allocate widget with width -23 and height 27

(notification-daemon:2443): GLib-CRITICAL **: Source ID 16 was not found when attempting to remove it

Program received signal SIGTRAP, Trace/breakpoint trap.
g_logv (log_domain=0x7ffff624bb6e "GLib", log_level=G_LOG_LEVEL_CRITICAL, format=<optimized out>, 
    args=args@entry=0x7fffffffdca8) at /tmp/buildd/glib2.0-2.40.0/./glib/gmessages.c:1038
1038	/tmp/buildd/glib2.0-2.40.0/./glib/gmessages.c: No such file or directory.
(gdb) bt
#0  g_logv (log_domain=0x7ffff624bb6e "GLib", log_level=G_LOG_LEVEL_CRITICAL, format=<optimized out>, 
    args=args@entry=0x7fffffffdca8) at /tmp/buildd/glib2.0-2.40.0/./glib/gmessages.c:1038
#1  0x00007ffff620dd72 in g_log (log_domain=log_domain@entry=0x7ffff624bb6e "GLib", 
    log_level=log_level@entry=G_LOG_LEVEL_CRITICAL, 
    format=format@entry=0x7ffff62533e0 "Source ID %u was not found when attempting to remove it")
    at /tmp/buildd/glib2.0-2.40.0/./glib/gmessages.c:1071
#2  0x00007ffff6205c5c in g_source_remove (tag=16) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:2194
#3  0x000000000040bab1 in ?? ()
#4  0x00007ffff64d63b8 in g_closure_invoke (closure=0x8b5a50, return_value=0x0, n_param_values=1, 
    param_values=0x7fffffffdf50, invocation_hint=0x7fffffffdef0)
    at /tmp/buildd/glib2.0-2.40.0/./gobject/gclosure.c:768
#5  0x00007ffff64e7d3d in signal_emit_unlocked_R (node=node@entry=0x629000, detail=detail@entry=0, 
    instance=instance@entry=0x98e2a0, emission_return=emission_return@entry=0x0, 
    instance_and_params=instance_and_params@entry=0x7fffffffdf50)
    at /tmp/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3551
#6  0x00007ffff64efa29 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, 
    detail=<optimized out>, var_args=var_args@entry=0x7fffffffe0d8)
    at /tmp/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3307
#7  0x00007ffff64efce2 in g_signal_emit (instance=instance@entry=0x98e2a0, signal_id=<optimized out>, 
    detail=detail@entry=0) at /tmp/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3363
#8  0x00007ffff77893f8 in gtk_widget_dispose (object=0x98e2a0)
    at /build/gtk+3.0-lhk9E2/gtk+3.0-3.12.2/./gtk/gtkwidget.c:11357
#9  0x00007ffff77962db in gtk_window_dispose (object=0x98e2a0)
    at /build/gtk+3.0-lhk9E2/gtk+3.0-3.12.2/./gtk/gtkwindow.c:2684
#10 0x00007ffff64dcad0 in g_object_run_dispose (object=0x98e2a0)
    at /tmp/buildd/glib2.0-2.40.0/./gobject/gobject.c:1073
#11 0x00000000004091ca in ?? ()
#12 0x00007ffff6207703 in g_timeout_dispatch (source=0x8b3f70, callback=<optimized out>, 
    user_data=<optimized out>) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:4472
#13 0x00007ffff6206ce5 in g_main_dispatch (context=0x649490) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3064
#14 g_main_context_dispatch (context=context@entry=0x649490) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3663
#15 0x00007ffff6207048 in g_main_context_iterate (context=0x649490, block=block@entry=1, 
    dispatch=dispatch@entry=1, self=<optimized out>) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3734
#16 0x00007ffff620730a in g_main_loop_run (loop=0x837b10) at /tmp/buildd/glib2.0-2.40.0/./glib/gmain.c:3928
#17 0x00007ffff764e735 in gtk_main () at /build/gtk+3.0-lhk9E2/gtk+3.0-3.12.2/./gtk/gtkmain.c:1192
---Type <return> to continue, or q <return> to quit---
#18 0x00000000004073da in ?? ()
#19 0x00007ffff5afbb45 in __libc_start_main (main=0x407350, argc=1, argv=0x7fffffffe458, init=<optimized out>, 
    fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffe448) at libc-start.c:287
#20 0x0000000000407445 in ?? ()
#21 0x00007fffffffe448 in ?? ()
#22 0x000000000000001c in ?? ()
#23 0x0000000000000001 in ?? ()
#24 0x00007fffffffe6d0 in ?? ()
#25 0x0000000000000000 in ?? ()
