Comment 2 for bug 1046668

StacktraceTop:
 g_str_hash (v=0x0) at /build/buildd/glib2.0-2.33.12/./glib/ghash.c:1730
 g_hash_table_lookup_node (hash_return=<synthetic pointer>, key=0x0, hash_table=0x979cae8) at /build/buildd/glib2.0-2.33.12/./glib/ghash.c:401
 g_hash_table_lookup (hash_table=0x979cae8, key=0x0) at /build/buildd/glib2.0-2.33.12/./glib/ghash.c:1074
 boxes_search_provider_GetResultMetas_co (_data_=0x97b10e8) at /extra-data/checkout/gnome/gnome-boxes/src/gnome-boxes-search-provider.vala:117
 g_simple_async_result_complete (simple=simple@entry=0x97ab4f8) at /build/buildd/glib2.0-2.33.12/./gio/gsimpleasyncresult.c:775