#0  0x00007f4e0c9d474d in poll () at ../sysdeps/unix/syscall-template.S:81
  [Error: ../sysdeps/unix/syscall-template.S was not found in source tree]
#1  0x00007f4e0d44ad34 in g_main_context_poll (priority=2147483647, n_fds=4, fds=0x17c1d90, timeout=29999, context=0x177d230) at /build/buildd/glib2.0-2.39.3/./glib/gmain.c:4008
  [Error: /build/buildd/glib2.0-2.39.3/./glib/gmain.c was not found in source tree]
#2  g_main_context_iterate (context=0x177d230, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/buildd/glib2.0-2.39.3/./glib/gmain.c:3709
  [Error: /build/buildd/glib2.0-2.39.3/./glib/gmain.c was not found in source tree]
#3  0x00007f4e0d44b05a in g_main_loop_run (loop=0x17c87a0) at /build/buildd/glib2.0-2.39.3/./glib/gmain.c:3908
  [Error: /build/buildd/glib2.0-2.39.3/./glib/gmain.c was not found in source tree]
#4  0x00007f4e0ecdc9b5 in gtk_main () at /build/buildd/gtk+3.0-3.10.6/./gtk/gtkmain.c:1158
  [Error: /build/buildd/gtk+3.0-3.10.6/./gtk/gtkmain.c was not found in source tree]
#5  0x0000000000405f5e in main (argc=1, argv=0x7fff7d0b91b8) at light-locker.c:105
  100:                         g_warning ("Unable to start screensaver");
  101:                 }
  102:                 exit (1);
  103:         }
  104: 
  105:         gtk_main ();
  106: 
  107:         g_object_unref (monitor);
  108: 
  109:         gs_debug ("light-locker finished");
  110: