Comment 8 for bug 1397130

the latest repro shows this stack trace if it helps.
Linux nubo-9 3.16.0-28-generic #37-Ubuntu SMP Mon Dec 8 17:15:28 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

root@nubo-9:/var/crash# dpkg -l |grep cgm
ii cgmanager 0.33-2 amd64 Central cgroup manager daemon
ii cgmanager-tests 0.33-2 all Central cgroup manager daemon (tests)
ii libcgmanager-dev:amd64 0.33-2 amd64 Central cgroup manager daemon (dev)
ii libcgmanager0:amd64 0.33-2 amd64 Central cgroup manager daemon (client library)

root@nubo-9:/var/crash# dpkg -l|grep libvirt
ii libvirt-bin 1.2.8-0ubuntu11.1 amd64 programs for the libvirt library
ii libvirt0 1.2.8-0ubuntu11.1 amd64 library for interfacing with different virtualization systems
hi nova-compute-libvirt 1:2014.2-0ubuntu1 all OpenStack Compute - compute node libvirt support
ii python-libvirt 1.2.8-0ubuntu2 amd64 libvirt Python bindings

# dpkg -l |grep dbus
ii dbus 1.8.8-1ubuntu2.1 amd64 simple interprocess messaging system (daemon and utilities)
ii dbus-1-dbg:amd64 1.8.8-1ubuntu2.1 amd64 simple interprocess messaging system (debug symbols)
ii dbus-x11 1.8.8-1ubuntu2.1 amd64 simple interprocess messaging system (X11 deps)
ii libdbus-1-3:amd64 1.8.8-1ubuntu2.1 amd64 simple interprocess messaging system (library)
ii libdbus-1-dev:amd64 1.8.8-1ubuntu2.1 amd64 simple interprocess messaging system (development headers)
ii libdbus-glib-1-2:amd64 0.102-1 amd64 simple interprocess messaging system (GLib-based shared library)
ii libnih-dbus-dev:amd64 1.0.3-4ubuntu26 amd64 NIH D-Bus Bindings Library (development files)
ii libnih-dbus1:amd64 1.0.3-4ubuntu26 amd64 NIH D-Bus Bindings Library
ii nih-dbus-tool 1.0.3-4ubuntu26 amd64 NIH D-Bus Binding Tool
ii python3-dbus 1.2.0-2build2 amd64 simple interprocess messaging system (Python 3 interface)

2014-12-12 05:27:01.331+0000: 35353: error : cgm_dbus_connect:76 : cgmanager: Error pinging manager: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
process 35331: The last reference on a connection was dropped without closing the connection. This is a bug in an application. See dbus_connection_unref() documentation for details.
Most likely, the application was supposed to call dbus_connection_close(), since this is a private connection.
2014-12-12 05:27:01.333+0000: 35358: error : cgm_dbus_connect:76 : cgmanager: Error pinging manager: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
(null):dbus_error.c:69: Unhandled error from nih_dbus_error_raise: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

Program received signal SIGABRT, Aborted.
[Switching to Thread 0x7f342dd40700 (LWP 35356)]
0x00007f3440d2fd27 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
56 ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0 0x00007f3440d2fd27 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1 0x00007f3440d31418 in __GI_abort () at abort.c:89
#2 0x00007f343eaa1997 in ?? () from /lib/x86_64-linux-gnu/libnih.so.1
#3 0x00007f343eaa1be1 in _nih_error_raise_error () from /lib/x86_64-linux-gnu/libnih.so.1
#4 0x00007f343ecb46e5 in cgmanager_get_pid_cgroup_sync () from /lib/x86_64-linux-gnu/libcgmanager.so.0
#5 0x00007f344134802b in ?? () from /usr/lib/libvirt.so.0
#6 0x00007f344133fa3b in ?? () from /usr/lib/libvirt.so.0
#7 0x00007f3441340c53 in ?? () from /usr/lib/libvirt.so.0
#8 0x00007f3441340ec7 in virCgroupNewDetectMachine () from /usr/lib/libvirt.so.0
#9 0x00007f3431a7dec5 in qemuConnectCgroup () from /usr/lib/libvirt/connection-driver/libvirt_driver_qemu.so
#10 0x00007f3431a92447 in ?? () from /usr/lib/libvirt/connection-driver/libvirt_driver_qemu.so
#11 0x00007f344139194e in ?? () from /usr/lib/libvirt.so.0
#12 0x00007f34410c60a5 in start_thread (arg=0x7f342dd40700) at pthread_create.c:309
#13 0x00007f3440df377d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111