Description of problem:
systemd process core file analyse:
 
#0  0x00007f1eff0bfa5d in pause () from /lib64/libpthread.so.0
#1  0x00007f1f00eb95dd in freeze () at src/shared/util.c:3522
#2  0x00007f1f00e4d02b in crash (sig=<optimized out>) at src/core/main.c:199
#3  <signal handler called>
#4  0x00007f1efed25989 in raise () from /lib64/libc.so.6
#5  0x00007f1efed27098 in abort () from /lib64/libc.so.6
#6  0x00007f1eff513f45 in _dbus_abort () at dbus-sysdeps.c:94
#7  0x00007f1eff50a7ce in _dbus_warn_check_failed (
    format=0x7f1eff51a3c0 "arguments to %s() were incorrect, assertion \"%s\" failed in file %s line %d.\nThis is normally a bug in some application using the D-Bus library.\n") at dbus-internals.c:290
#8  0x00007f1eff4fcb86 in dbus_message_iter_append_basic (iter=0x7fffeec6fb60, type=type@entry=115, value=value@entry=0x7fffeec6f9f0) at dbus-message.c:2586
#9  0x00007f1f00ebee64 in bus_property_append_string (i=<optimized out>, property=<optimized out>, data=<optimized out>) at src/shared/dbus-common.c:526
#10 0x00007f1f00ec000f in bus_default_message_handler (c=c@entry=0x7f1f030407d0, message=message@entry=0x7f1f03044190, 
    introspection=introspection@entry=0x7f1f00f148a8 "<!DOCTYPE node PUBLIC \"-//freedesktop//DTD D-BUS Object Introspection 1.0//EN\"\n\"http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd\">\n<node>\n <interface name=\"org.freedesktop.systemd1.Unit\">\n"..., interfaces=interfaces@entry=0x7f1f00f16650 "org.freedesktop.DBus.Properties", 
    bound_properties=bound_properties@entry=0x7fffeec6fc20) at src/shared/dbus-common.c:390
#11 0x00007f1f00ed2eab in bus_scope_message_handler (u=0x7f1f02d168a0, c=0x7f1f030407d0, message=0x7f1f03044190) at src/core/dbus-scope.c:94
#12 0x00007f1f00e8b347 in bus_unit_message_dispatch (message=0x7f1f03044190, connection=0x7f1f030407d0, u=0x7f1f02d168a0) at src/core/dbus-unit.c:479
#13 bus_unit_message_handler (connection=0x7f1f030407d0, message=message@entry=0x7f1f03044190, data=data@entry=0x7f1f02d05a10) at src/core/dbus-unit.c:610
#14 0x00007f1eff500c86 in _dbus_object_tree_dispatch_and_unlock (tree=0x7f1f02d11f90, message=message@entry=0x7f1f03044190, found_object=found_object@entry=0x7fffeec6ff14)
    at dbus-object-tree.c:862
#15 0x00007f1eff4f2e49 in dbus_connection_dispatch (connection=connection@entry=0x7f1f030407d0) at dbus-connection.c:4672
#16 0x00007f1f00e82dba in bus_dispatch (m=m@entry=0x7f1f02d05a10) at src/core/dbus.c:525
#17 0x00007f1f00e53b12 in manager_loop (m=0x7f1f02d05a10) at src/core/manager.c:1858
#18 0x00007f1f00e4b03c in main (argc=5, argv=0x7fffeec709e8) at src/core/main.c:1667
(gdb) frame 8
#8  0x00007f1eff4fcb86 in dbus_message_iter_append_basic (iter=0x7fffeec6fb60, type=type@entry=115, value=value@entry=0x7fffeec6f9f0) at dbus-message.c:2586
2586      _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
(gdb) p *(DBusMessageRealIter *) 0x7fffeec6fb60
$1 = {message = 0x7f1f03042820, changed_stamp = 0, iter_type = 7, sig_refcount = 3, u = {writer = {byte_order = 108, container_type = 118, type_pos_is_expectation = 1, 
      enabled = 1, type_str = 0x7f1f03042870, type_pos = 2512, value_str = 0x7f1f03042870, value_pos = 2516, u = {array = {start_pos = 8, len_pos = 0, 
          element_type_pos = 1}}}, reader = {byte_order = 108, finished = 0, array_len_offset = 3, type_str = 0x7f1f03042870, type_pos = 2512, value_str = 0x7f1f03042870, 
      value_pos = 2516, klass = 0x100000000, u = {array = {start_pos = 0}}}}}


Version-Release number of selected component (if applicable):


How reproducible:
I am not clear...