(gdb) bt full
#0  0x00007ffff6dd7d95 in raise () from /lib/libc.so.6
No symbol table info available.
#1  0x00007ffff6dd95ba in abort () from /lib/libc.so.6
No symbol table info available.
#2  0x00007ffff7bb48e5 in _dbus_abort () at dbus-sysdeps.c:94
        s = <value optimized out>
#3  0x00007ffff7b9c321 in _dbus_real_assert (condition=<value optimized out>, condition_text=0x7ffff7bc6dc0 "slot < allocator->n_allocated_slots", 
    file=0x7ffff7bc6b30 "dbus-dataslot.c", line=309, func=<value optimized out>) at dbus-internals.c:902
No locals.
#4  0x00007ffff7b98c8d in _dbus_data_slot_list_get (allocator=0x7ffff7ddc960, list=0x6cb4d0, slot=1) at dbus-dataslot.c:309
        __FUNCTION__ = "_dbus_data_slot_list_get"
#5  0x00007ffff7b71d92 in dbus_connection_get_data (connection=0x6cb450, slot=1) at dbus-connection.c:5984
        res = <value optimized out>
        __FUNCTION__ = "dbus_connection_get_data"
#6  0x0000000000448ae2 in bus_connection_has_subscriber (m=0x6c81d0, c=0x6cb450) at src/dbus.c:1632
        __PRETTY_FUNCTION__ = "bus_connection_has_subscriber"
#7  0x000000000044896b in bus_has_subscriber (m=0x6c81d0) at src/dbus.c:1618
        i = 0xffffffffffffffff
        c = 0x6cb450
        __PRETTY_FUNCTION__ = "bus_has_subscriber"
#8  0x0000000000479e5c in unit_add_to_dbus_queue (u=0x6e8d50) at src/unit.c:302
        __PRETTY_FUNCTION__ = "unit_add_to_dbus_queue"
#9  0x000000000047efb1 in unit_add_dependency (u=0x6e8d50, d=UNIT_AFTER, other=0x6e9cc0, add_reference=true) at src/unit.c:1450
        inverse_table = {UNIT_REQUIRED_BY, UNIT_REQUIRED_BY_OVERRIDABLE, UNIT_REQUIRED_BY, UNIT_REQUIRED_BY_OVERRIDABLE, UNIT_WANTED_BY, _UNIT_DEPENDENCY_INVALID, 
          _UNIT_DEPENDENCY_INVALID, _UNIT_DEPENDENCY_INVALID, UNIT_CONFLICTED_BY, UNIT_CONFLICTS, UNIT_AFTER, UNIT_BEFORE, _UNIT_DEPENDENCY_INVALID, 
          UNIT_REFERENCED_BY, UNIT_REFERENCES}
        r = 1
        q = 1
        v = 1
        w = 1
        __PRETTY_FUNCTION__ = "unit_add_dependency"
#10 0x000000000047f0ce in unit_add_two_dependencies (u=0x6e8d50, d=UNIT_AFTER, e=UNIT_REQUIRES, other=0x6e9cc0, add_reference=true) at src/unit.c:1471
        r = 0
        __PRETTY_FUNCTION__ = "unit_add_two_dependencies"
#11 0x000000000047f56c in unit_add_two_dependencies_by_name (u=0x6e8d50, d=UNIT_AFTER, e=UNIT_REQUIRES, name=0x490fc0 "basic.target", path=0x0, add_reference=true)
    at src/unit.c:1548
        other = 0x6e9cc0
        r = 0
        s = 0x0
        __PRETTY_FUNCTION__ = "unit_add_two_dependencies_by_name"
#12 0x000000000042312b in service_add_default_dependencies (s=0x6e8d50) at src/service.c:871
        r = 0
        __PRETTY_FUNCTION__ = "service_add_default_dependencies"
#13 0x00000000004233e9 in service_load (u=0x6e8d50) at src/service.c:931
        r = 0
        s = 0x6e8d50
        __PRETTY_FUNCTION__ = "service_load"
#14 0x000000000047c627 in unit_load (u=0x6e8d50) at src/unit.c:788
        r = -1
        __PRETTY_FUNCTION__ = "unit_load"
        __func__ = "unit_load"
#15 0x00000000004118b5 in manager_dispatch_load_queue (m=0x6c81d0) at src/manager.c:1608
        meta = 0x6e8d50
        n = 0
        __PRETTY_FUNCTION__ = "manager_dispatch_load_queue"
#16 0x0000000000429781 in service_enumerate (m=0x6c81d0) at src/service.c:2763
        p = 0x6ca1b8
        i = 7
        d = 0x6d2f60
        path = 0x6dbe70 "/etc/rc.d/rc6.d"
        fpath = 0x6e0810 "/etc/rc.d/rc6.d/S60sendsignals"
        name = 0x6cc1b0 "sendsignals.service"
        runlevel_services = {0x0, 0x6e2430, 0x6e2860, 0x6e3880, 0x6e3f20, 0x6e5310, 0x6e88e0}
        shutdown_services = 0x6e45c0
        service = 0x6e7660
        j = 0x6d2b30
        r = 1
        __PRETTY_FUNCTION__ = "service_enumerate"
        __func__ = "service_enumerate"
#17 0x000000000040d57b in manager_enumerate (m=0x6c81d0) at src/manager.c:473
        r = 0
        q = 0
        c = UNIT_SERVICE
        __PRETTY_FUNCTION__ = "manager_enumerate"
#18 0x000000000040d9e2 in manager_startup (m=0x6c81d0, serialization=0x0, fds=0x0) at src/manager.c:574
        r = 0
        q = 7
        __PRETTY_FUNCTION__ = "manager_startup"
#19 0x000000000040b1de in main (argc=4, argv=0x7fffffffec58) at src/main.c:1027
        m = 0x6c81d0
        r = 0
        retval = 1
        fds = 0x0
        reexecute = false
        __func__ = "main"
        __PRETTY_FUNCTION__ = "main"