#0  0x00007ffe1336d445 in __GI_raise (sig=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
        resultvar = 0
        pid = <optimized out>
        selftid = 1970
#1  0x00007ffe13370bab in __GI_abort () at abort.c:91
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x18, sa_sigaction = 0x18}, sa_mask = {__val = {140729225009129, 140729220586568, 140729255587840, 1024, 0, 18022784, 4294967296, 4294967295, 0, 165, 18138976, 3092568, 0, 18240256, 18239968, 140729224470528}}, sa_flags = 355096436, sa_restorer = 0x5}
        sigs = {__val = {32, 0 <repeats 15 times>}}
#2  0x00007ffe13759dad in g_assertion_message (domain=<optimized out>, file=<optimized out>, line=<optimized out>, func=0x7ffe14e06c60 "_tp_channel_contacts_handle_owners_changed", message=0x1126410 "assertion failed: (self->priv->group_contact_owners != NULL)") at /build/buildd/glib2.0-2.31.20/./glib/gtestutils.c:1860
        lstr = "743\000\377\177\000\000\200\370\031\345\377\177\000\000\350\265\025\001\000\000\000\000\360i\340\024\376\177\000"
        s = 0x114c760 "\020]\026\001"
#3  0x00007ffe1375a2d2 in g_assertion_message_expr (domain=0x7ffe14def4c6 "tp-glib", file=0x7ffe14e06a7b "channel-contacts.c", line=743, func=0x7ffe14e06c60 "_tp_channel_contacts_handle_owners_changed", expr=<optimized out>) at /build/buildd/glib2.0-2.31.20/./glib/gtestutils.c:1871
        s = <optimized out>
#4  0x00007ffe14d32b56 in _tp_channel_contacts_handle_owners_changed (self=0x1145830, added=<optimized out>, removed=0x1147b60, identifiers=0x11651e0) at channel-contacts.c:743
        data = <optimized out>
        contacts = <optimized out>
        __PRETTY_FUNCTION__ = "_tp_channel_contacts_handle_owners_changed"
#5  0x00007ffe14d0cba4 in _tp_cli_channel_interface_group_invoke_callback_for_handle_owners_changed_detailed (tpproxy=0x1145830, error=<optimized out>, args=0x11302e0, generic_callback=0x7ffe14d33be0 <tp_channel_handle_owners_changed_detailed_cb>, user_data=<optimized out>, weak_object=<optimized out>) at _gen/tp-cli-channel-body.h:3246
        callback = 0x7ffe14d33be0 <tp_channel_handle_owners_changed_detailed_cb>
#6  0x00007ffe14dc283c in tp_proxy_signal_invocation_run (p=0x1133da0) at proxy-signals.c:268
        invocation = 0x1133da0
        popped = <optimized out>
#7  0x00007ffe13739dda in g_main_dispatch (context=0x10115e0) at /build/buildd/glib2.0-2.31.20/./glib/gmain.c:2510
        dispatch = 0x7ffe13737a30 <g_idle_dispatch>
        was_in_call = 0
        user_data = 0x1133da0
        callback = 0x7ffe14dc27e0 <tp_proxy_signal_invocation_run>
        cb_funcs = 0x7ffe139e59a0
        cb_data = 0x1156510
        current_source_link = {data = 0x11571c0, next = 0x0}
        need_destroy = <optimized out>
        source = 0x11571c0
        current = 0x10841a0
        i = <optimized out>
#8  g_main_context_dispatch (context=0x10115e0) at /build/buildd/glib2.0-2.31.20/./glib/gmain.c:3047
No locals.
#9  0x00007ffe1373a1a0 in g_main_context_iterate (dispatch=1, block=<optimized out>, context=0x10115e0, self=<optimized out>) at /build/buildd/glib2.0-2.31.20/./glib/gmain.c:3118
        timeout = 0
        some_ready = 1
        fds = <optimized out>
        max_priority = -100
        nfds = 0
        allocated_nfds = <optimized out>
#10 g_main_context_iterate (context=0x10115e0, block=<optimized out>, dispatch=1, self=<optimized out>) at /build/buildd/glib2.0-2.31.20/./glib/gmain.c:3055
        some_ready = 1
#11 0x00007ffe1373a59a in g_main_loop_run (loop=0x1017f90) at /build/buildd/glib2.0-2.31.20/./glib/gmain.c:3312
        __PRETTY_FUNCTION__ = "g_main_loop_run"
#12 0x000000000040e8e5 in main (argc=<optimized out>, argv=<optimized out>) at mc-server.c:86
        mcd = 0x1018010