openstack - devstack failing on Ubuntu14.04

I am trying to install openstack using devstack on Ubuntu 14.04. I am facing the error shown below:

2014-11-20 12:05:03.300 | + mysql -uroot -popenstack -h172.16.69.217 -e 'DROP DATABASE IF EXISTS nova;'
2014-11-20 12:05:03.303 | + mysql -uroot -popenstack -h172.16.69.217 -e 'CREATE DATABASE nova CHARACTER SET latin1;'
2014-11-20 12:05:03.307 | + /usr/local/bin/nova-manage db sync

2014-11-20 12:05:03.539 | Traceback (most recent call last):
2014-11-20 12:05:03.539 |   File "/usr/local/bin/nova-manage", line 6, in 
2014-11-20 12:05:03.539 |     from nova.cmd.manage import main
2014-11-20 12:05:03.539 |   File "/opt/stack/nova/nova/cmd/manage.py", line 68, in 
2014-11-20 12:05:03.539 |     from nova.api.ec2 import ec2utils
2014-11-20 12:05:03.539 |   File "/opt/stack/nova/nova/api/ec2/__init__.py", line 32, in 
2014-11-20 12:05:03.539 |     from nova.api.ec2 import apirequest
2014-11-20 12:05:03.539 |   File "/opt/stack/nova/nova/api/ec2/apirequest.py", line 29, in 
2014-11-20 12:05:03.539 |     from nova.api.ec2 import ec2utils
2014-11-20 12:05:03.539 |   File "/opt/stack/nova/nova/api/ec2/ec2utils.py", line 28, in 

2014-11-20 12:05:03.539 |     from nova.objects import base as obj_base
2014-11-20 12:05:03.540 |   File "/opt/stack/nova/nova/objects/base.py", line 35, in 
2014-11-20 12:05:03.540 |     from nova import utils
2014-11-20 12:05:03.540 |   File "/opt/stack/nova/nova/utils.py", line 39, in 
2014-11-20 12:05:03.540 |     from oslo.concurrency import lockutils
2014-11-20 12:05:03.540 |   File "/usr/local/lib/python2.7/dist-packages/oslo/concurrency/lockutils.py", line 30, in 
2014-11-20 12:05:03.540 |     from oslo.config import cfgfilter
2014-11-20 12:05:03.540 | ImportError: cannot import name cfgfilter

Could anyone help me with this issue?