我们正在尝试安装 OpenStack服务。我们已经创建了虚拟环境并安装了Pip。 Pip版本是8.1.1。现在，当我们尝试安装keystone时，我们得到了依赖包的错误，如下所示：
/tmp/openstack-venv-builder/venvs/horizon/bin/pip install --timeout 120 --find-links /var/www/repo/os-releases/liberty --no-index --log /var/log/repo/repo_venv_builder.log keystone
Ignoring indexes: http://pypi.python.org/simple
Collecting keystone
Collecting oslo.i18n<1.6.0,>=1.5.0 (from keystone)
Could not find a version that satisfies the requirement oslo.i18n<1.6.0,>=1.5.0 (from keystone) (from versions: 3.1.0)
No matching distribution found for oslo.i18n<1.6.0,>=1.5.0 (from keystone)
oslo.i18n 上的安装看起来不错。
/tmp/openstack-venv-builder/venvs/horizon/bin/pip install --timeout 120 --find-links /var/www/repo/os-releases/liberty --no-index --log /var/log/repo/repo_venv_builder.log oslo.i18n
Ignoring indexes: http://pypi.python.org/simple
Collecting oslo.i18n
Collecting pbr>=1.6 (from oslo.i18n)
Collecting Babel>=1.3 (from oslo.i18n)
Collecting six>=1.9.0 (from oslo.i18n)
Collecting pytz>=0a (from Babel>=1.3->oslo.i18n)
Installing collected packages: pbr, pytz, Babel, six, oslo.i18n
Successfully installed Babel-2.1.1 oslo.i18n-3.1.0 pbr-1.8.1 pytz-2015.7 six-1.10.0
Even then we are getting error while installing keystone. Please help.