On Centos 7.2 3.10.0-327.10.1.el7.x86_64 #1 SMP Tue Feb 16 17:03:50 UTC 2016 x86_64
./stack.sh
...
HEAD is now at c665080... Make WebSSO trusted_dashboard hostname case-insensitive
2016-02-18 19:18:27.960 | + git branch -D stable/liberty
2016-02-18 19:18:27.962 | Deleted branch stable/liberty (was c665080).
2016-02-18 19:18:27.962 | + git checkout -b stable/liberty
2016-02-18 19:18:27.997 | Switched to a new branch 'stable/liberty'
2016-02-18 19:18:27.998 | + cd /opt/stack/keystone
2016-02-18 19:18:27.998 | + git show --oneline
2016-02-18 19:18:27.998 | + head -1
2016-02-18 19:18:28.004 | c665080 Make WebSSO trusted_dashboard hostname case-insensitive
2016-02-18 19:18:28.005 | + cd /home/stack/Program-Files/CentOS/DevStack/git-devstack
2016-02-18 19:18:28.005 | + setup_develop /opt/stack/keystone
2016-02-18 19:18:28.005 | + local project_dir=/opt/stack/keystone
2016-02-18 19:18:28.005 | + setup_package_with_constraints_edit /opt/stack/keystone -e
2016-02-18 19:18:28.005 | + local project_dir=/opt/stack/keystone
2016-02-18 19:18:28.005 | + local flags=-e
2016-02-18 19:18:28.005 | + '[' -n /opt/stack/requirements ']'
2016-02-18 19:18:28.005 | ++ awk '/^name.*=/ {print $3}' /opt/stack/keystone/setup.cfg
2016-02-18 19:18:28.007 | + local name=keystone
2016-02-18 19:18:28.007 | + /opt/stack/requirements/.venv/bin/edit-constraints /opt/stack/requirements/upper-constraints.txt -- keystone '-e file:///opt/stack/keystone#egg=keystone'
2016-02-18 19:18:28.114 | + setup_package /opt/stack/keystone -e
2016-02-18 19:18:28.115 | + local project_dir=/opt/stack/keystone
2016-02-18 19:18:28.115 | + local flags=-e
2016-02-18 19:18:28.115 | + pip_install -e /opt/stack/keystone
2016-02-18 19:18:28.737 | + sudo -H http_proxy= https_proxy= no_proxy= PIP_FIND_LINKS= /usr/bin/pip install -c /opt/stack/requirements/upper-constraints.txt --upgrade -e /opt/stack/keystone
2016-02-18 19:18:29.331 | Ignoring dnspython3: markers "python_version=='3.4'" don't match your environment
2016-02-18 19:18:29.531 | Obtaining file:///opt/stack/keystone
2016-02-18 19:18:30.418 | Complete output from command python setup.py egg_info:
2016-02-18 19:18:30.418 | ERROR:root:Error parsing
2016-02-18 19:18:30.418 | Traceback (most recent call last):
2016-02-18 19:18:30.418 | File "/usr/lib/python2.7/site-packages/pbr/core.py", line 109, in pbr
2016-02-18 19:18:30.418 | attrs = util.cfg_to_args(path)
2016-02-18 19:18:30.418 | File "/usr/lib/python2.7/site-packages/pbr/util.py", line 261, in cfg_to_args
2016-02-18 19:18:30.419 | wrap_commands(kwargs)
2016-02-18 19:18:30.419 | File "/usr/lib/python2.7/site-packages/pbr/util.py", line 541, in wrap_commands
2016-02-18 19:18:30.419 | for cmd, _ in dist.get_command_list():
2016-02-18 19:18:30.419 | File "/usr/lib/python2.7/site-packages/setuptools/dist.py", line 447, in get_command_list
2016-02-18 19:18:30.419 | cmdclass = ep.resolve()
2016-02-18 19:18:30.419 | File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2386, in resolve
2016-02-18 19:18:30.419 | module = __import__(self.module_name, fromlist=['__name__'], level=0)
2016-02-18 19:18:30.419 | File "/usr/lib/python2.7/site-packages/sphinx/setup_command.py", line 23, in <module>
2016-02-18 19:18:30.419 | from sphinx.application import Sphinx
2016-02-18 19:18:30.419 | File "/usr/lib/python2.7/site-packages/sphinx/application.py", line 30, in <module>
2016-02-18 19:18:30.419 | from sphinx import package_dir, locale
2016-02-18 19:18:30.419 | File "/usr/lib/python2.7/site-packages/sphinx/locale/__init__.py", line 15, in <module>
2016-02-18 19:18:30.419 | from six.moves import UserString
2016-02-18 19:18:30.419 | ImportError: cannot import name UserString
2016-02-18 19:18:30.419 | error in setup command: Error parsing /opt/stack/keystone/setup.cfg: ImportError: cannot import name UserString
2016-02-18 19:18:30.419 |
2016-02-18 19:18:30.419 | ----------------------------------------
2016-02-18 19:18:30.419 | Command "python setup.py egg_info" failed with error code 1 in /opt/stack/keystone
2016-02-18 19:18:30.476 | You are using pip version 7.1.2, however version 8.0.2 is available.
2016-02-18 19:18:30.476 | You should consider upgrading via the 'pip install --upgrade pip' command.
2016-02-18 19:18:30.523 | + exit_trap
2016-02-18 19:18:30.523 | + local r=1
2016-02-18 19:18:30.524 | ++ jobs -p
2016-02-18 19:18:30.524 | + jobs=
2016-02-18 19:18:30.524 | + [[ -n '' ]]
2016-02-18 19:18:30.524 | + kill_spinner
2016-02-18 19:18:30.524 | + '[' '!' -z '' ']'
2016-02-18 19:18:30.524 | + [[ 1 -ne 0 ]]
2016-02-18 19:18:30.524 | + echo 'Error on exit'
2016-02-18 19:18:30.524 | Error on exit
2016-02-18 19:18:30.524 | + generate-subunit 1455822972 138 fail
2016-02-18 19:18:30.816 | + [[ -z /opt/stack/logs ]]
2016-02-18 19:18:30.816 | + /home/stack/Program-Files/CentOS/DevStack/git-devstack/tools/worlddump.py -d /opt/stack/logs
2016-02-18 19:18:31.130 | + exit 1
The whole log is provided below.
It seems this error occured because of the fact that your pip is not upgraded.
I guess trying the command
pip install --upgrade pip
could help.