On MacOS, with Python 3.7 installed due to `brew install tox`'s pull-in of python3.7:

```
Collecting zVMCloudConnector===1.2.2 (from -c https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt (line 144))
  Downloading https://files.pythonhosted.org/packages/a1/da/f5a4432ebcbb630ce9a25d0ec81599fff7e473b5df7f73595783e39dba2d/zVMCloudConnector-1.2.2.tar.gz (183kB)
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/nv/_0qtnvt10tbdjp6gzftkq6dc0000gn/T/pip-install-0tbgqgae/zVMCloudConnector/setup.py", line 18, in <module>
        from zvmsdk import version as sdkversion
      File "/private/var/folders/nv/_0qtnvt10tbdjp6gzftkq6dc0000gn/T/pip-install-0tbgqgae/zVMCloudConnector/zvmsdk/version.py", line 29, in <module>
        raise RuntimeError('On Python 3, zvm sdk supports to Python 3.6')
    RuntimeError: On Python 3, zvm sdk supports to Python 3.6
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/nv/_0qtnvt10tbdjp6gzftkq6dc0000gn/T/pip-install-0tbgqgae/zVMCloudConnector/

fast8 installed: appdirs==1.4.3,asn1crypto==0.24.0,atomicwrites==1.1.5,attrs==18.1.0,Babel==2.6.0,bandit==1.4.0,certifi==2018.4.16,cffi==1.11.5,chardet==3.0.4,cliff==2.13.0,cmd2==0.9.3,colorama==0.3.9,coverage==4.5.1,cryptography==2.3,ddt==1.2.0,debtcollector==1.20.0,decorator==4.3.0,deprecation==2.0.5,dogpile.cache==0.6.6,enum-compat==0.0.2,eventlet==0.20.0,extras==1.0.0,fasteners==0.14.1,fixtures==3.0.0,flake8==2.5.5,future==0.16.0,gabbi==1.44.0,gitdb2==2.0.4,GitPython==2.1.11,greenlet==0.4.14,hacking==0.12.0,idna==2.7,iso8601==0.1.12,jmespath==0.9.3,jsonpatch==1.23,jsonpath-rw==1.4.0,jsonpath-rw-ext==1.1.3,jsonpointer==2.0,jsonschema==2.6.0,keystoneauth1==3.10.0,linecache2==1.0.0,lxml==4.2.3,mccabe==0.2.1,mock==2.0.0,monotonic==1.5,more-itertools==4.2.0,mox3==0.26.0,msgpack==0.5.6,munch==2.3.2,netaddr==0.7.19,netifaces==0.10.7,openstacksdk==0.17.0,os-client-config==1.31.2,os-service-types==1.2.0,osc-lib==1.11.0,oslo.concurrency==3.27.0,oslo.config==6.4.0,oslo.i18n==3.21.0,oslo.serialization==2.27.0,oslo.utils==3.36.4,oslo.vmware==2.31.0,oslotest==3.6.0,osprofiler==2.3.0,packaging==17.1,pbr==4.1.1,pep8==1.5.7,pluggy==0.6.0,ply==3.11,prettytable==0.7.2,psycopg2==2.7.5,py==1.5.4,pycparser==2.18,pyflakes==0.8.1,PyMySQL==0.9.2,pyparsing==2.2.0,pyperclip==1.6.4,pytest==3.6.3,python-barbicanclient==4.6.0,python-ironicclient==2.4.0,python-mimeparse==1.6.0,python-subunit==1.3.0,pytz==2018.5,PyYAML==3.13,requests==2.19.1,requests-mock==1.5.2,requestsexceptions==1.4.0,rfc3986==1.1.0,simplejson==3.16.0,six==1.11.0,smmap2==2.0.4,stestr==2.1.0,stevedore==1.29.0,suds-jurko==0.6,testresources==2.0.1,testscenarios==0.5.0,testtools==2.3.0,traceback2==1.4.0,unittest2==1.1.0,urllib3==1.23,voluptuous==0.11.1,wcwidth==0.1.7,WebOb==1.8.2,wrapt==1.10.11,wsgi-intercept==1.8.0
__________________________________________________________________________________________________________________________________________________________ summary ___________________________________________________________________________________________________________________________________________________________
ERROR:   fast8: InvocationError for command /Users/jpipes/src/git.openstack.org/openstack/nova/.tox/fast8/bin/pip install -chttps://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt -e /Users/jpipes/src/git.openstack.org/openstack/nova (see /Users/jpipes/src/git.openstack.org/openstack/nova/.tox/fast8/log/fast8-2.log) (exited with code 1)
UNKNOWN-10-89-82-X:nova jpipes$ git log --oneline | head -n1
d07694b28c Merge "Make host_aggregate_map dictionary case-insensitive"
UNKNOWN-10-89-82-X:nova jpipes$ git checkout master && git pull
Already on 'master'
Your branch is up to date with 'origin/master'.
Already up to date.
UNKNOWN-10-89-82-X:nova jpipes$ python3 --version
Python 3.7.0
```