After enabling the insert emoji WebKitGTK action in the composer's context menu for Geary, I'm seeing the following critical when clicking on an emoji from the recent list in the emoji chooser:

 ![crt] 23:24:31.0646 Gtk:gtk_widget_is_ancestor: assertion 'GTK_IS_WIDGET (widget)' failed

Thread 1 "geary" received signal SIGTRAP, Trace/breakpoint trap.
_g_log_abort (breakpoint=1) at ../../../glib/gmessages.c:554
554	in ../../../glib/gmessages.c
(gdb) bt
#0  0x00007ffff7d348e5 in _g_log_abort (breakpoint=1) at ../../../glib/gmessages.c:554
#1  0x00007ffff7d35bb9 in g_logv
    (log_domain=0x7ffff7468047 "Gtk", log_level=G_LOG_LEVEL_CRITICAL, format=<optimised out>, args=args@entry=0x7fffffffd4e0) at ../../../glib/gmessages.c:1373
#2  0x00007ffff7d35d83 in g_log
    (log_domain=log_domain@entry=0x7ffff7468047 "Gtk", log_level=log_level@entry=G_LOG_LEVEL_CRITICAL, format=format@entry=0x7ffff7d86713 "%s: assertion '%s' failed")
    at ../../../glib/gmessages.c:1415
#3  0x00007ffff7d3657d in g_return_if_fail_warning
    (log_domain=log_domain@entry=0x7ffff7468047 "Gtk", pretty_function=pretty_function@entry=0x7ffff74ec050 <__func__.77293> "gtk_widget_is_ancestor", expression=expression@entry=0x7ffff74680a7 "GTK_IS_WIDGET (widget)") at ../../../glib/gmessages.c:2771
#4  0x00007ffff740c22a in gtk_widget_is_ancestor
    (widget=widget@entry=0x0, ancestor=ancestor@entry=0x555559600440 [WebKitEmojiChooser])
    at ../../../../gtk/gtkwidget.c:11845
#5  0x00007ffff731bd3c in gtk_popover_button_release
    (widget=widget@entry=0x555559600440 [WebKitEmojiChooser], event=event@entry=0x5555595e8010) at ../../../../gtk/gtkpopover.c:1569
#6  0x00007ffff745b7ff in _gtk_marshal_BOOLEAN__BOXEDv
    (closure=0x555555d8b3b0, return_value=0x7fffffffd7e0, instance=<optimised out>, args=<optimised out>, marshal_data=<optimised out>, n_params=<optimised out>, param_types=0x555555d8ab00) at gtkmarshalers.c:129
#7  0x00007ffff7e19936 in _g_closure_invoke_va
    (closure=0x555555d8b3b0, return_value=0x7fffffffd7e0, instance=0x555559600440, args=0x7fffffffd8b0, n_params=1, param_types=0x555555d8ab00) at ../../../gobject/gclosure.c:873
#8  0x00007ffff7e35dcb in g_signal_emit_valist
    (instance=0x555559600440, signal_id=<optimised out>, detail=<optimised out>, var_args=var_args@entry=0x7fffffffd8b0) at ../../../gobject/gsignal.c:3306
#9  0x00007ffff7e369b3 in g_signal_emit
    (instance=instance@entry=0x555559600440, signal_id=<optimised out>, detail=detail@entry=0) at ../../../gobject/gsignal.c:3453
#10 0x00007ffff7405e53 in gtk_widget_event_internal
    (event=0x5555595e8010, widget=0x555559600440 [WebKitEmojiChooser])
    at ../../../../gtk/gtkwidget.c:7789
#11 0x00007ffff7405e53 in gtk_widget_event_internal
    (widget=0x555559600440 [WebKitEmojiChooser], event=0x5555595e8010)
    at ../../../../gtk/gtkwidget.c:7658
#12 0x00007ffff72c19d8 in propagate_event_up
    (topmost=<optimised out>, event=<optimised out>, widget=0x555559600440 [WebKitEmojiChooser]) at ../../../../gtk/gtkmain.c:2594
#13 0x00007ffff72c19d8 in propagate_event
    (widget=<optimised out>, event=0x5555595e8010, captured=<optimised out>, topmost=0x0)
--Type <RET> for more, q to quit, c to continue without paging--
    at ../../../../gtk/gtkmain.c:2697
#14 0x00007ffff72c3c2b in gtk_main_do_event (event=0x5555595e8010)
    at ../../../../gtk/gtkmain.c:1917
#15 0x00007ffff72c3c2b in gtk_main_do_event (event=<optimised out>)
    at ../../../../gtk/gtkmain.c:1687
#16 0x00007ffff7c15f19 in _gdk_event_emit (event=event@entry=0x5555595e8010)
    at ../../../../gdk/gdkevents.c:73
#17 0x00007ffff7c74446 in gdk_event_source_dispatch
    (base=<optimised out>, callback=<optimised out>, data=<optimised out>)
    at ../../../../../gdk/wayland/gdkeventsource.c:124
#18 0x00007ffff7d2e84d in g_main_dispatch (context=0x555555d066e0)
    at ../../../glib/gmain.c:3179
#19 0x00007ffff7d2e84d in g_main_context_dispatch (context=context@entry=0x555555d066e0)
    at ../../../glib/gmain.c:3844
#20 0x00007ffff7d2ead0 in g_main_context_iterate
    (context=context@entry=0x555555d066e0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimised out>) at ../../../glib/gmain.c:3917
#21 0x00007ffff7d2eb73 in g_main_context_iteration
    (context=context@entry=0x555555d066e0, may_block=may_block@entry=1)
    at ../../../glib/gmain.c:3978
#22 0x00007ffff78b8b05 in g_application_run
    (application=0x555555cf3160 [ApplicationClient], argc=<optimised out>, argv=<optimised out>) at ../../../gio/gapplication.c:2559
#23 0x00005555555f6ce7 in _vala_main (args=0x7fffffffdd68, args_length1=3)
    at ../src/client/application/main.vala:36
#24 0x00005555555f6d4b in main (argc=3, argv=0x7fffffffdd68)
    at ../src/client/application/main.vala:7