Program received signal SIGSEGV, Segmentation fault.
0x4613ffbc in gtk_widget_get_window (widget=0xa96994b0) at /usr/src/debug/gtk+3/3.20.9-r0/gtk+-3.20.9/gtk/gtkwidget.c:15947
15947	  g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);
(gdb) where
#0  0x4613ffbc in gtk_widget_get_window (widget=0xa96994b0) at /usr/src/debug/gtk+3/3.20.9-r0/gtk+-3.20.9/gtk/gtkwidget.c:15947
#1  0x460f0798 in _gtk_widget_find_at_coords (window=window@entry=0xa27c6e40, window_x=<optimized out>, window_y=<optimized out>, widget_x=widget_x@entry=0xbeffda9c, 
    widget_y=widget_y@entry=0xbeffdaa0) at /usr/src/debug/gtk+3/3.20.9-r0/gtk+-3.20.9/gtk/gtktooltip.c:637
#2  0x460f14fc in gtk_tooltip_show_tooltip (display=display@entry=0xb6d241a0) at /usr/src/debug/gtk+3/3.20.9-r0/gtk+-3.20.9/gtk/gtktooltip.c:1117
#3  0x460f19e0 in tooltip_popup_timeout (data=0xb6d241a0) at /usr/src/debug/gtk+3/3.20.9-r0/gtk+-3.20.9/gtk/gtktooltip.c:1228
#4  0x45c1956c in gdk_threads_dispatch (data=<optimized out>) at /usr/src/debug/gtk+3/3.20.9-r0/gtk+-3.20.9/gdk/gdk.c:720
#5  0xb696887c in g_timeout_dispatch (source=0x973d1540, callback=0x45c19540 <gdk_threads_dispatch>, user_data=<optimized out>)
    at /usr/src/debug/glib-2.0/1_2.46.2-r0/glib-2.46.2/glib/gmain.c:4577
#6  0xb6967c1c in g_main_dispatch (context=0xb6d206a0) at /usr/src/debug/glib-2.0/1_2.46.2-r0/glib-2.46.2/glib/gmain.c:3154
#7  g_main_context_dispatch (context=context@entry=0xb6d206a0) at /usr/src/debug/glib-2.0/1_2.46.2-r0/glib-2.46.2/glib/gmain.c:3769
#8  0xb6967fb0 in g_main_context_iterate (context=context@entry=0xb6d206a0, block=block@entry=0, dispatch=dispatch@entry=1, self=<optimized out>)
    at /usr/src/debug/glib-2.0/1_2.46.2-r0/glib-2.46.2/glib/gmain.c:3840
#9  0xb696805c in g_main_context_iteration (context=0xb6d206a0, may_block=0) at /usr/src/debug/glib-2.0/1_2.46.2-r0/glib-2.46.2/glib/gmain.c:3901
#10 0xb4fcdb90 in nsAppShell::ProcessNextNativeEvent(bool) () from /usr/lib/firefox-52.1.0/libxul.so
#11 0xb4fa4960 in nsBaseAppShell::DoProcessNextNativeEvent(bool) () from /usr/lib/firefox-52.1.0/libxul.so
#12 0xb4fa6ee0 in nsBaseAppShell::OnProcessNextEvent(nsIThreadInternal*, bool) () from /usr/lib/firefox-52.1.0/libxul.so
#13 0xb3ab181c in nsThread::ProcessNextEvent(bool, bool*) () from /usr/lib/firefox-52.1.0/libxul.so
#14 0xb3abb4b8 in NS_InvokeByIndex () from /usr/lib/firefox-52.1.0/libxul.so
#15 0xbeffddc8 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

