(gdb) bt
#0  0x00007f3df93be849 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1  0x00007f3df93bfcd8 in __GI_abort () at abort.c:89
#2  0x00007f3df93fd114 in __libc_message (do_abort=do_abort@entry=2, fmt=fmt@entry=0x7f3df94f30e0 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/posix/libc_fatal.c:175
#3  0x00007f3df940296e in malloc_printerr (action=3, str=0x7f3df94ef17b "free(): invalid pointer", ptr=<optimized out>) at malloc.c:4916
#4  0x00007f3dfaba48ee in g_free (mem=0x1bf3c70) at gmem.c:195
#5  0x00007f3dfe20ff6a in clutter_input_device_dispose (gobject=0x1862610) at ./clutter-input-device.c:84
#6  0x00007f3dfaeb7900 in g_object_unref (_object=0x1862610) at gobject.c:3146
#7  0x00007f3dfab88454 in g_hash_table_remove_node (hash_table=0x19600c0, i=6, notify=1) at ghash.c:448
#8  0x00007f3dfab89563 in g_hash_table_remove_internal (hash_table=0x19600c0, key=0x6, notify=1) at ghash.c:1288
#9  0x00007f3dfab895af in g_hash_table_remove (hash_table=0x19600c0, key=0x6) at ghash.c:1316
#10 0x00007f3dfe1a949f in remove_device (manager_xi2=0x186cdf0, device_id=6) at ./x11/clutter-device-manager-xi2.c:390
#11 0x00007f3dfe1a9608 in translate_hierarchy_event (backend_x11=0x17fa0e0, manager_xi2=0x186cdf0, ev=0x3383bd0) at ./x11/clutter-device-manager-xi2.c:426
#12 0x00007f3dfe1aa0d8 in clutter_device_manager_xi2_translate_event (translator=0x186cdf0, native=0x7fff2d9adb80, event=0x333db40) at ./x11/clutter-device-manager-xi2.c:792
#13 0x00007f3dfe26919f in _clutter_event_translator_translate_event (translator=0x186cdf0, native=0x7fff2d9adb80, translated=0x333db40) at ./clutter-event-translator.c:37
#14 0x00007f3dfe1e29f0 in clutter_backend_real_translate_event (backend=0x17fa0e0, native=0x7fff2d9adb80, event=0x333db40) at ./clutter-backend.c:629
#15 0x00007f3dfe19fc8e in clutter_backend_x11_translate_event (backend=0x17fa0e0, native=0x7fff2d9adb80, event=0x333db40) at ./x11/clutter-backend-x11.c:667
#16 0x00007f3dfe1e3d94 in _clutter_backend_translate_event (backend=0x17fa0e0, native=0x7fff2d9adb80, event=0x333db40) at ./clutter-backend.c:1308
#17 0x00007f3dfe1a2185 in clutter_x11_handle_event (xevent=0x7fff2d9adb80) at ./x11/clutter-event-x11.c:199
#18 0x00007f3dfedbfb85 in _meta_plugin_xevent_filter (plugin=0x1dcf030, xev=0x7fff2d9adb80) at compositor/meta-plugin.c:195
#19 0x00007f3dfedc05e9 in meta_plugin_manager_xevent_filter (plugin_mgr=0x1e24510, xev=0x7fff2d9adb80) at compositor/meta-plugin-manager.c:315
#20 0x00007f3dfedbaacf in meta_compositor_process_event (compositor=0x1e19fc0, event=0x7fff2d9adb80, window=0x0) at compositor/compositor.c:976
#21 0x00007f3dfedd6468 in event_callback (event=0x7fff2d9adb80, data=0x1d179b0) at core/display.c:3098
#22 0x00007f3dfee4dc62 in filter_func (xevent=0x7fff2d9adb80, event=0x333dcf0, data=0x1d297f0) at ui/ui.c:253
#23 0x00007f3dfc59d03b in gdk_event_apply_filters (xevent=0x7fff2d9adb80, event=0x333dcf0, window=0x0) at gdkeventsource.c:81
#24 0x00007f3dfc59d3d4 in gdk_event_source_translate_event (event_source=0x18324c0, xevent=0x7fff2d9adb80) at gdkeventsource.c:195
#25 0x00007f3dfc59d757 in _gdk_x11_display_queue_events (display=0x1831020) at gdkeventsource.c:338
#26 0x00007f3dfc560f82 in gdk_display_get_event (display=0x1831020) at gdkdisplay.c:325
#27 0x00007f3dfc59d7f5 in gdk_event_source_dispatch (source=0x18324c0, callback=0x0, user_data=0x0) at gdkeventsource.c:360
#28 0x00007f3dfab9c396 in g_main_dispatch (context=0x17fd340) at gmain.c:3068
#29 0x00007f3dfab9d0b6 in g_main_context_dispatch (context=0x17fd340) at gmain.c:3643
#30 0x00007f3dfab9d2a8 in g_main_context_iterate (context=0x17fd340, block=1, dispatch=1, self=0x1864460) at gmain.c:3714
#31 0x00007f3dfab9d6d1 in g_main_loop_run (loop=0x17f7540) at gmain.c:3908
#32 0x00007f3dfeded4fe in meta_run () at core/main.c:556
#33 0x00000000004029f7 in main (argc=1, argv=0x7fff2d9adfd8) at main.c:433
