ceilometer-api fail to start due to no module wsme found by devstack

With latest commit ceilometer: 23ff2f9bbfc14e435c4c04ddddfba473cf2a829b and devstack: 60ffc6165037827ecae3208f79c69aca74fa46bf , ceilometer-api fail to start, it reported:

stack@ubuntu:/opt/stack$ cd /opt/stack/ceilometer && /opt/stack/ceilometer/bin/ceilometer-api -d -v --log-dir=/var/log/ceilometer-api --config-file /etc/ceilometer/ceilometer.conf || touch "/opt/stack/status/stack/ceilometer-api.failure"
2012-12-13 11:35:09 25944 CRITICAL ceilometer [-] No module named wsme
2012-12-13 11:35:09 25944 TRACE ceilometer Traceback (most recent call last):
2012-12-13 11:35:09 25944 TRACE ceilometer File "/opt/stack/ceilometer/bin/ceilometer-api", line 51, in <module>
2012-12-13 11:35:09 25944 TRACE ceilometer extra_hooks=[acl.AdminAuthHook()])
2012-12-13 11:35:09 25944 TRACE ceilometer File "/opt/stack/ceilometer/ceilometer/api/app.py", line 43, in setup_app
2012-12-13 11:35:09 25944 TRACE ceilometer wrap_app=middleware.ParsableErrorMiddleware,
2012-12-13 11:35:09 25944 TRACE ceilometer File "/usr/local/lib/python2.7/dist-packages/pecan/__init__.py", line 38, in make_app
2012-12-13 11:35:09 25944 TRACE ceilometer app = Pecan(root, **kw)
2012-12-13 11:35:09 25944 TRACE ceilometer File "/usr/local/lib/python2.7/dist-packages/pecan/core.py", line 193, in __init__
2012-12-13 11:35:09 25944 TRACE ceilometer root = self.__translate_root__(root)
2012-12-13 11:35:09 25944 TRACE ceilometer File "/usr/local/lib/python2.7/dist-packages/pecan/core.py", line 217, in __translate_root__
2012-12-13 11:35:09 25944 TRACE ceilometer module = __import__(name, fromlist=fromlist)
2012-12-13 11:35:09 25944 TRACE ceilometer File "/opt/stack/ceilometer/ceilometer/api/controllers/root.py", line 21, in <module>
2012-12-13 11:35:09 25944 TRACE ceilometer from . import v2
2012-12-13 11:35:09 25944 TRACE ceilometer File "/opt/stack/ceilometer/ceilometer/api/controllers/v2.py", line 85, in <module>
2012-12-13 11:35:09 25944 TRACE ceilometer import wsme
2012-12-13 11:35:09 25944 TRACE ceilometer ImportError: No module named wsme