Here is a full backtrace:

#0  0x000055555555b684 in  ()
#1  0x000055555555bc23 in  ()
#6  0x00007ffff671cfbf in <emit signal ??? on instance 0x555555803040 [XfceTitledDialog]> (instance=instance@entry=0x555555803040, signal_id=<optimised out>, detail=detail@entry=0) at ././gobject/gsignal.c:3447
        var_args = {{gp_offset = 32, fp_offset = 48, overflow_arg_area = 0x7fffffffe1d0, reg_save_area = 0x7fffffffe110}}
    #2  0x00007ffff749892c in _gtk_marshal_BOOLEAN__BOXED (closure=0x5555559e3f20, return_value=0x7fffffffded0, n_param_values=<optimised out>, param_values=0x7fffffffdf30, invocation_hint=<optimised out>, marshal_data=<optimised out>) at gtkmarshalers.c:86
                callback = 0x55555555bb40
                cc = 0x5555559e3f20
                data1 = 0x555555803040
                data2 = <optimised out>
                v_return = <optimised out>
                __func__ = "_gtk_marshal_BOOLEAN__BOXED"
    #3  0x00007ffff6701f75 in g_closure_invoke (closure=0x5555559e3f20, return_value=return_value@entry=0x7fffffffded0, n_param_values=2, param_values=param_values@entry=0x7fffffffdf30, invocation_hint=invocation_hint@entry=0x7fffffffdeb0) at ././gobject/gclosure.c:804
                marshal = <optimised out>
                marshal_data = <optimised out>
                in_marshal = 0
                real_closure = 0x5555559e3f00
                __func__ = "g_closure_invoke"
    #4  0x00007ffff6714053 in signal_emit_unlocked_R (node=node@entry=0x5555557eaf70, detail=detail@entry=0, instance=instance@entry=0x555555803040, emission_return=emission_return@entry=0x7fffffffe040, instance_and_params=instance_and_params@entry=0x7fffffffdf30) at ././gobject/gsignal.c:3705
                tmp = <optimised out>
                handler = 0x5555559e2340
                accumulator = 0x5555557eada0
                emission = 
                  {next = 0x0, instance = 0x555555803040, ihint = {signal_id = 53, detail = 0, run_type = G_SIGNAL_RUN_LAST}, state = EMISSION_RUN, chain_type = 4}
                handler_list = <optimised out>
                return_accu = 0x7fffffffded0
                accu = 
                      {g_type = 20, data = {{v_int = 0, v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer = 0x0}, {v_int = 0, v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer = 0x0}}}
                signal_id = 53
                max_sequential_handler_number = 171
                return_value_altered = 1
    #5  0x00007ffff671c67f in g_signal_emit_valist (instance=<optimised out>, signal_id=<optimised out>, detail=<optimised out>, var_args=var_args@entry=0x7fffffffe0f0) at ././gobject/gsignal.c:3401
                return_value = 
                      {g_type = 20, data = {{v_int = 0, v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer = 0x0}, {v_int = 0, v_uint = 0, v_long = 0, v_ulong = 0, v_int64 = 0, v_uint64 = 0, v_float = 0, v_double = 0, v_pointer = 0x0}}}
                error = 0x0
                rtype = 20
                static_scope = 0
                instance_and_params = 0x7fffffffdf30
                signal_return_type = <optimised out>
                param_values = 0x7fffffffdf48
                i = <optimised out>
                n_params = <optimised out>
                __func__ = "g_signal_emit_valist"
#7  0x00007ffff75b0f1c in gtk_widget_event_internal (widget=widget@entry=0x555555803040 [XfceTitledDialog], event=event@entry=0x5555559d6800)
    at ./gtk/gtkwidget.c:5017
        signal_num = <optimised out>
        return_val = 0
#8  0x00007ffff75b11e7 in IA__gtk_widget_event (widget=widget@entry=0x555555803040 [XfceTitledDialog], event=event@entry=0x5555559d6800)
    at ./gtk/gtkwidget.c:4814
        __func__ = "IA__gtk_widget_event"
#9  0x00007ffff7497683 in IA__gtk_main_do_event (event=0x5555559d6800) at ./gtk/gtkmain.c:1664
        event_widget = 0x555555803040 [XfceTitledDialog]
        grab_widget = 0x555555803040 [XfceTitledDialog]
        window_group = 0x555555856d60 [GtkWindowGroup]
        rewritten_event = <optimised out>
        tmp_list = <optimised out>
        __func__ = "IA__gtk_main_do_event"
#10 0x00007ffff710ccac in gdk_event_dispatch (source=<optimised out>, callback=<optimised out>, user_data=<optimised out>) at ./gdk/x11/gdkevents-x11.c:2425
        display = <optimised out>
        event = 0x5555559d6800
#11 0x00007ffff59cc8a7 in g_main_dispatch (context=0x5555557e3d30) at ././glib/gmain.c:3203
        dispatch = 0x7ffff710cc60 <gdk_event_dispatch>
        prev_source = 0x0
        was_in_call = 0
        user_data = 0x0
        callback = 0x0
        cb_funcs = <optimised out>
        cb_data = <optimised out>
        need_destroy = <optimised out>
        source = 0x5555557e3c40
        current = 0x55555587ba10
        i = 0
#12 0x00007ffff59cc8a7 in g_main_context_dispatch (context=context@entry=0x5555557e3d30) at ././glib/gmain.c:3856
#13 0x00007ffff59ccb10 in g_main_context_iterate (context=0x5555557e3d30, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimised out>)
    at ././glib/gmain.c:3929
        max_priority = 0
        timeout = 0
        some_ready = 1
        nfds = 3
        allocated_nfds = 3
        fds = <optimised out>
#14 0x00007ffff59cce32 in g_main_loop_run (loop=0x5555559f0640) at ././glib/gmain.c:4125
        __func__ = "g_main_loop_run"
#15 0x00007ffff7496507 in IA__gtk_main () at ./gtk/gtkmain.c:1282
        tmp_list = 0x0
        functions = 0x0
        init = <optimised out>
        loop = 0x5555559f0640
#16 0x0000555555560c11 in  ()
#17 0x000055555555abd1 in  ()
#18 0x00007ffff53bd3f1 in __libc_start_main (main=
    0x55555555a900, argc=1, argv=0x7fffffffe5d8, init=<optimised out>, fini=<optimised out>, rtld_fini=<optimised out>, stack_end=0x7fffffffe5c8)
    at ../csu/libc-start.c:291
        result = <optimised out>
        unwind_buf = 
              {cancel_jmp_buf = {{jmp_buf = {0, 7555255544880342420, 93824992260720, 140737488348624, 0, 0, 4435198665904399764, 4435175062162023828}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x7fffffffe5e8, 0x7ffff7ffe168}, data = {prev = 0x0, cleanup = 0x0, canceltype = -6680}}}
        not_first_call = <optimised out>
#19 0x000055555555b29a in  ()