Comment 14 for bug 1383370

I'm very happy that I resolved this issue.

Beacuse Devstack always install the relations with the certain version from config file.
For example, pip version come from /home/stack/devstack/tools/cap-pip.txt
if pip<8, the devstack will uninstall pip 8.1.2 and install pip 7.1.2. However, your program need pip 8.1.2, this bug come.

if you change pip<8 to pip<9, this issue will be resolved. But there will be more problems about version.

Actually, the main point is that, you write the wrong format in local.conf. Maybe your devstack version is kilo or liberty, but you fill your local.conf from openstack website, the config form website is for the latest version of devstack, that is different from other versions.

for example. the config about ceilometer
website:
enable_plugin ceilometer https://git.openstack.org/openstack/ceilometer

liberty:
enable_service ceilometer-acompute ceilometer-acentral ceilometer-collector ceilometer-api
enable_service ceilometer-alarm-notify ceilometer-alarm-eval
enable_service ceilometer-anotification

In a word, you should fill right config in local.conf for your devstack version, all the version problems will go away.