I am experiencing what appears to be the same problem:

+ /usr/local/bin/nova-manage --config-file /etc/nova/nova.conf network create private 10.0.0.0/24 1 256
2013-06-27 07:05:54.727 INFO nova.network.driver [-] Loading network driver 'nova.network.linux_net'
2013-06-27 07:05:54.742 DEBUG nova.servicegroup.api [-] ServiceGroup driver defined as an instance of db from (pid=8162) __new__ /opt/stack/nova/nova/servicegroup/api.py:61
2013-06-27 07:05:56.255 DEBUG nova.openstack.common.lockutils [req-335b63a5-c272-4f82-a285-3597539b681e None None] Got semaphore "dbapi_backend" for method "__get_backend"... from (pid=8162) inner /opt/stack/nova/nova/openstack/common/lockutils.py:190
Command failed, please check log for more info
2013-06-27 07:06:07.694 CRITICAL nova [-] 'module' object has no attribute 'packs'
2013-06-27 07:06:07.694 TRACE nova Traceback (most recent call last):
2013-06-27 07:06:07.694 TRACE nova   File "/usr/local/bin/nova-manage", line 9, in <module>
2013-06-27 07:06:07.694 TRACE nova     load_entry_point('nova==2013.2.a1401.gcefb051', 'console_scripts', 'nova-manage')()
2013-06-27 07:06:07.694 TRACE nova   File "/opt/stack/nova/nova/cmd/manage.py", line 1303, in main
2013-06-27 07:06:07.694 TRACE nova     rpc.cleanup()
2013-06-27 07:06:07.694 TRACE nova   File "/opt/stack/nova/nova/openstack/common/rpc/__init__.py", line 240, in cleanup
2013-06-27 07:06:07.694 TRACE nova     return _get_impl().cleanup()
2013-06-27 07:06:07.694 TRACE nova   File "/opt/stack/nova/nova/openstack/common/rpc/__init__.py", line 301, in _get_impl
2013-06-27 07:06:07.694 TRACE nova     _RPCIMPL = importutils.import_module(CONF.rpc_backend)
2013-06-27 07:06:07.694 TRACE nova   File "/opt/stack/nova/nova/openstack/common/importutils.py", line 58, in import_module
2013-06-27 07:06:07.694 TRACE nova     __import__(import_str)
2013-06-27 07:06:07.694 TRACE nova   File "/opt/stack/nova/nova/openstack/common/rpc/impl_kombu.py", line 30, in <module>
2013-06-27 07:06:07.694 TRACE nova     import kombu.messaging
2013-06-27 07:06:07.694 TRACE nova   File "/usr/lib/python2.7/dist-packages/kombu/messaging.py", line 17, in <module>
2013-06-27 07:06:07.694 TRACE nova     from .serialization import encode
2013-06-27 07:06:07.694 TRACE nova   File "/usr/lib/python2.7/dist-packages/kombu/serialization.py", line 332, in <module>
2013-06-27 07:06:07.694 TRACE nova     register_msgpack()
2013-06-27 07:06:07.694 TRACE nova   File "/usr/lib/python2.7/dist-packages/kombu/serialization.py", line 314, in register_msgpack
2013-06-27 07:06:07.694 TRACE nova     registry.register('msgpack', msgpack.packs, msgpack.unpacks,
2013-06-27 07:06:07.694 TRACE nova AttributeError: 'module' object has no attribute 'packs'
2013-06-27 07:06:07.694 TRACE nova 
++ failed
++ local r=1
+++ jobs -p
++ kill
++ set +o xtrace
linux@ubuntu:~/devstack$ 


I tried applying the patch as indicated in https://review.openstack.org/32787 but to no avail. Here are the that commands I ran before getting the error:

$ git clone git://github.com/openstack-dev/devstack.git
$ cd devstack
$ git fetch https://review.openstack.org/openstack/ceilometer refs/changes/87/32787/1 && git format-patch -1 --stdout FETCH_HEAD
$  ./stack.sh


Am I missing something obvious? Apologies if this is a stupid question but I really need some help here. Thanks in advance!