#0  0x00007ff8a22ff518 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
  [Error: raise.c was not found in source tree]
#1  0x00007ff8a23010ea in __GI_abort () at abort.c:89
  [Error: abort.c was not found in source tree]
#2  0x00007ff8a2920d25 in g_assertion_message () from /tmp/apport_sandbox_4UzMDi/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ff8a2920dba in g_assertion_message_expr () from /tmp/apport_sandbox_4UzMDi/lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007ff8a28e9c3e in g_hash_table_lookup () from /tmp/apport_sandbox_4UzMDi/lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007ff882a16662 in cc_appearance_xml_load_xml_internal (xml=xml@entry=0x172d3a0, filename=filename@entry=0x17c6080 "/usr/share/gnome-background-properties/xenial-wallpapers.xml", in_thread=in_thread@entry=0) at cc-appearance-xml.c:303
  298:       uri = g_filename_to_uri (filename, NULL, NULL);
  299:       id = g_strdup_printf ("%s#%s", uri, cname);
  300:       g_free (uri);
  301: 
  302:       /* Make sure we don't already have this one and that filename exists */
  303:       if (g_hash_table_lookup (xml->priv->wp_hash, id) != NULL) {
  304: 	g_object_unref (item);
  305: 	g_free (id);
  306: 	continue;
  307:       }
  308: 
#6  0x00007ff882a16adb in gnome_wp_file_changed (monitor=<optimized out>, file=<optimized out>, other_file=<optimized out>, event_type=<optimized out>, data=0x172d3a0) at cc-appearance-xml.c:337
  332: 
  333:   switch (event_type) {
  334:   case G_FILE_MONITOR_EVENT_CHANGED:
  335:   case G_FILE_MONITOR_EVENT_CREATED:
  336:     filename = g_file_get_path (file);
  337:     cc_appearance_xml_load_xml_internal (data, filename, FALSE);
  338:     g_free (filename);
  339:     break;
  340:   default:
  341:     break;
  342:   }
#7  0x00007ff89df2ee40 in ffi_call_unix64 () from /tmp/apport_sandbox_4UzMDi/usr/lib/x86_64-linux-gnu/libffi.so.6
#8  0x00007ff89df2e8ab in ffi_call () from /tmp/apport_sandbox_4UzMDi/usr/lib/x86_64-linux-gnu/libffi.so.6
#9  0x00007ff8a2bd2cf5 in g_cclosure_marshal_generic_va () from /tmp/apport_sandbox_4UzMDi/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#10 0x00007ff8a2bd21d4 in _g_closure_invoke_va () from /tmp/apport_sandbox_4UzMDi/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#11 0x00007ff8a2bec9a6 in g_signal_emit_valist () from /tmp/apport_sandbox_4UzMDi/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#12 0x00007ff8a2bed08f in g_signal_emit () from /tmp/apport_sandbox_4UzMDi/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#13 0x00007ff8a2f13029 in g_file_monitor_source_dispatch () from /tmp/apport_sandbox_4UzMDi/usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#14 0x00007ff8a28fb137 in g_main_context_dispatch () from /tmp/apport_sandbox_4UzMDi/lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007ff8a28fb390 in g_main_context_iterate.isra () from /tmp/apport_sandbox_4UzMDi/lib/x86_64-linux-gnu/libglib-2.0.so.0
#16 0x00007ff8a28fb43c in g_main_context_iteration () from /tmp/apport_sandbox_4UzMDi/lib/x86_64-linux-gnu/libglib-2.0.so.0
#17 0x00007ff8a2ec2ccd in g_application_run () from /tmp/apport_sandbox_4UzMDi/usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#18 0x0000000000407503 in main (argc=2, argv=0x7ffc320cc158) at control-center.c:317
  312:   g_signal_connect (application, "startup",
  313:                     G_CALLBACK (application_startup_cb), shell);
  314:   g_signal_connect (application, "command-line",
  315:                     G_CALLBACK (application_command_line_cb), shell);
  316: 
  317:   status = g_application_run (G_APPLICATION (application), argc, argv);
  318: 
  319:   g_object_unref (application);
  320: 
  321:   return status;
  322: }