Comment 4 for bug 1816022

The backport was merged, so now tempest list-plugins is correctly executed.

But the problem is that tempest-17.0 is installed instead of the master version, probably because the constraints are enforced. So now the execution fails because the --black-regex= option is not recognized:

/opt/stack/tempest/.tox/tempest/local/lib/python2.7/site-packages/setuptools/dist.py:47: DistDeprecationWarning: Do not call this function
  warnings.warn("Do not call this function", DistDeprecationWarning)
all develop-inst-noop: /opt/stack/tempest
all installed: DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7.,appdirs==1.4.3,asn1crypto==0.22.0,Babel==2.3.4,bcrypt==3.1.3,certifi==2017.4.17,cffi==1.10.0,chardet==3.0.4,cliff==2.8.2,cmd2==0.7.5,contextlib2==0.5.5,cryptography==2.0.2,debtcollector==1.17.1,deprecation==1.0.1,enum34==1.1.6,extras==1.0.0,fasteners==0.14.1,fixtures==3.0.0,funcsigs==1.0.2,functools32==3.2.3.post2,future==0.17.1,futures==3.1.1,idna==2.5,ipaddress==1.0.18,iso8601==0.1.11,jsonpatch==1.16,jsonpointer==1.10,jsonschema==2.6.0,keystoneauth1==3.1.0,linecache2==1.0.0,Mako==1.0.7,MarkupSafe==1.0,mock==2.0.0,monotonic==1.3,mox3==0.23.0,msgpack==0.6.1,msgpack-python==0.4.8,netaddr==0.7.19,netifaces==0.10.6,openstacksdk==0.9.17,os-client-config==1.28.0,os-testr==1.0.0,osc-lib==1.7.0,oslo.concurrency==3.21.1,oslo.config==4.11.1,oslo.context==2.17.1,oslo.i18n==3.17.1,oslo.log==3.30.2,oslo.serialization==2.20.2,oslo.utils==3.28.3,oslotest==2.17.1,paramiko==2.2.1,pbr==3.1.1,positional==1.1.2,prettytable==0.7.2,pyasn1==0.3.1,pycparser==2.18,pyinotify==0.9.6,PyNaCl==1.1.2,pyOpenSSL==17.2.0,pyparsing==2.2.0,pyperclip==1.5.27,python-cinderclient==3.1.1,python-dateutil==2.6.1,python-glanceclient==2.8.0,python-keystoneclient==3.13.0,python-mimeparse==1.6.0,python-neutronclient==6.5.0,python-novaclient==9.1.2,python-openstackclient==3.12.1,python-saharaclient==1.3.0,python-subunit==1.2.0,python-swiftclient==3.4.0,pytz==2017.2,PyYAML==3.12,requests==2.18.2,requestsexceptions==1.3.0,rfc3986==1.1.0,sahara-tests==0.7.1.dev19,simplejson==3.11.1,six==1.10.0,stestr==2.0.0,stevedore==1.25.1,subprocess32==3.5.3,# Editable Git install with no remote (tempest==19.0.1.dev319),-e /opt/stack/tempest,testrepository==0.0.20,testtools==2.3.0,traceback2==1.4.0,unicodecsv==0.14.1,unittest2==1.1.0,urllib3==1.22,voluptuous==0.10.5,warlock==1.2.0,wcwidth==0.1.7,wrapt==1.10.10
all run-test-pre: PYTHONHASHSEED='417735469'
all runtests: commands[0] | find . -type f -name '*.pyc' -delete
all runtests: commands[1] | tempest run --regex '^(sahara_tempest_plugin.tests.)' --concurrency=4 --black-regex=
usage: tempest run [-h] [--workspace WORKSPACE]
                   [--workspace-path WORKSPACE_PATH]
                   [--config-file CONFIG_FILE] [--smoke | --regex REGEX]
                   [--whitelist-file WHITELIST_FILE | --blacklist-file BLACKLIST_FILE | --load-list LOAD_LIST]
                   [--list-tests] [--concurrency CONCURRENCY]
                   [--parallel | --serial] [--save-state] [--subunit]
                   [--combine]
tempest run: error: unrecognized arguments: --black-regex=
ERROR: InvocationError for command '/opt/stack/tempest/.tox/tempest/bin/tempest run --regex ^(sahara_tempest_plugin.tests.) --concurrency=4 --black-regex=' (exited with code 2)

What is the right solution then? Lower the requirements of tempest to make sure that it can be installed using the constraints of all supported stable branches?