[… cut …]
#6  malloc_printerr (str=str@entry=0x7ffff54a7ff0 "double free or corruption (!prev)") at malloc.c:5359
#7  0x00007ffff539671c in _int_free_merge_chunk (av=0x7ffff54d9ac0 , p=0x555555ac3f40, size=96) at malloc.c:4441
#8  0x00007ffff5396814 in _int_free_chunk
    (av=0x7ffff54d9ac0 , p=, size=, have_lock=) at malloc.c:4386
#9  0x00007ffff5ca59e2 in real_node_free (node=0x555555ac4180, seq=0x555555ac40b0) at ../glib/glib/gsequence.c:1837
#10 0x00007ffff5ca5a34 in node_free (node=, seq=0x555555ac40b0) at ../glib/glib/gsequence.c:1849
#11 g_sequence_free (seq=0x555555ac40b0) at ../glib/glib/gsequence.c:249
#12 0x00007ffff702237e in gtk_constraint_variable_set_free (set=0x555555a82a90) at ../gtk/gtk/gtkconstraintexpression.c:392
#13 0x00007ffff5c6eae9 in g_hash_table_remove_internal (hash_table=0x555555abb770 = {...}, key=, notify=1)
    at ../glib/glib/ghash.c:1730
#14 g_hash_table_remove (hash_table=0x555555abb770 = {...}, key=key@entry=0x555555ac3b60) at ../glib/glib/ghash.c:1758
#15 0x00007ffff702f053 in gtk_constraint_solver_remove_constraint (self=0x55555598ffa0, constraint=0x555555ac3b60)
    at ../gtk/gtk/gtkconstraintsolver.c:1925
#16 0x00007ffff6dfe8d2 in gtk_constraint_detach (constraint=0x555555ac3bc0) at ../gtk/gtk/gtkconstraint.c:592
#17 gtk_constraint_layout_unroot (manager=0x555555aa6370) at ../gtk/gtk/gtkconstraintlayout.c:1176
#18 0x00007ffff6fe3dc5 in gtk_layout_manager_set_root (root=, layout_manager=)
    at ../gtk/gtk/gtklayoutmanager.c:293
#19 gtk_layout_manager_set_root (layout_manager=, root=0x0) at ../gtk/gtk/gtklayoutmanager.c:280
#20 gtk_widget_unroot (widget=0x555555b29c60) at ../gtk/gtk/gtkwidget.c:2636
#21 0x00007ffff6fe3f65 in gtk_widget_forall (widget=0x555555957a90, callback=0x7ffff6fe3d20 , user_data=0x0)
    at ../gtk/gtk/gtkwidget.c:12572
#22 gtk_widget_real_unroot (widget=0x555555957a90) at ../gtk/gtk/gtkwidget.c:810
#23 0x00007ffff6fe3d79 in gtk_widget_unroot (widget=widget@entry=0x555555957a90) at ../gtk/gtk/gtkwidget.c:2628
#24 0x00007ffff6fe545c in gtk_widget_unparent (widget=0x555555957a90) at ../gtk/gtk/gtkwidget.c:2705
#25 0x00007ffff7005c99 in gtk_window_dispose (object=0x555555b37780) at ../gtk/gtk/gtkwindow.c:2739
#26 0x00007ffff6db15a9 in gtk_application_window_dispose (object=0x555555b37780) at ../gtk/gtk/gtkapplicationwindow.c:625
#27 0x00007ffff5d9ee36 in g_object_unref (_object=0x555555b37780) at ../glib/gobject/gobject.c:4839
#28 0x00007ffff6ea6b0e in gtk_widget_stack_free_elements (start=, end=) at ../gtk/gdk/gdkarrayimpl.c:109
#29 gtk_widget_stack_clear (self=0x7fffffffcd10) at ../gtk/gdk/gdkarrayimpl.c:118
#30 gtk_propagate_event_internal (widget=, 
    widget@entry=0x555555a6b090, event=event@entry=0x5555561f4830, topmost=) at ../gtk/gtk/gtkmain.c:2040
#31 0x00007ffff6ea6d05 in gtk_propagate_event (widget=widget@entry=0x555555a6b090, event=event@entry=0x5555561f4830)
    at ../gtk/gtk/gtkmain.c:2081
#32 0x00007ffff6ea7743 in gtk_main_do_event (event=0x5555561f4830) at ../gtk/gtk/gtkmain.c:1771
#38 0x00007ffff5dafc44 in 
    (instance=instance@entry=0x555555ad65f0, signal_id=, detail=detail@entry=0) at ../glib/gobject/gsignal.c:3624
    #33 0x00007ffff71b9ef8 in _gdk_marshal_BOOLEAN__POINTERv
    (closure=, return_value=0x7fffffffd100, instance=, args=, marshal_data=, n_params=, param_types=0x555555ad4fb0) at gdk/gdkmarshalers.c:302
    #34 0x00007ffff726390b in gdk_surface_event_marshallerv
    (closure=0x555555ae8c90, return_value=0x7fffffffd100, instance=0x555555ad65f0, args=0x7fffffffd1e0, marshal_data=0x0, n_params=1, param_types=0x555555ad4fb0) at ../gtk/gdk/gdksurface.c:465
    #35 0x00007ffff5dafa77 in _g_closure_invoke_va
    (closure=0x555555ae8c90, return_value=0x7fffffffd100, instance=0x555555ad65f0, args=0x7fffffffd1e0, n_params=1, param_types=0x555555ad4fb0) at ../glib/gobject/gclosure.c:980
    #36 signal_emit_valist_unlocked
    (instance=instance@entry=0x555555ad65f0, signal_id=signal_id@entry=159, detail=detail@entry=0, var_args=var_args@entry=0x7fffffffd1e0) at ../glib/gobject/gsignal.c:3465
    #37 0x00007ffff5dafb89 in g_signal_emit_valist
    (instance=0x555555ad65f0, signal_id=159, detail=0, var_args=var_args@entry=0x7fffffffd1e0) at ../glib/gobject/gsignal.c:3304
#39 0x00007ffff726a6b2 in gdk_surface_handle_event.isra.0 (event=event@entry=0x5555561f4830) at ../gtk/gdk/gdksurface.c:3003
#40 0x00007ffff71c05bc in _gdk_event_emit (event=0x5555561f4830) at ../gtk/gdk/gdkevents.c:491
#41 gdk_event_source_dispatch (source=, callback=, user_data=)
    at ../gtk/gdk/broadway/gdkeventsource.c:378
#42 0x00007ffff5c83f4d in g_main_dispatch (context=0x5555558a4370) at ../glib/glib/gmain.c:3591
#43 0x00007ffff5c85607 in g_main_context_dispatch_unlocked (context=0x5555558a4370) at ../glib/glib/gmain.c:4451
#44 g_main_context_iterate_unlocked
    (context=context@entry=0x5555558a4370, block=block@entry=1, dispatch=dispatch@entry=1, self=)
    at ../glib/glib/gmain.c:4516
#45 0x00007ffff5c85815 in g_main_context_iteration (context=context@entry=0x5555558a4370, may_block=may_block@entry=1)
    at ../glib/glib/gmain.c:4582
#46 0x00007ffff5eb9f26 in g_application_run (application=0x5555558a14f0, argc=, argv=)
    at ../glib/gio/gapplication.c:2742
#47 0x00005555555b0b83 in main (argc=1, argv=0x7fffffffd6f8) at src/main.cxx:189