`pip install opsview` fails with current python/pip

[ramayer]

I get these errors when I try on Ubuntu 21.04

testing:/tmp$ python -m venv /tmp/opsview_venv
testing:/tmp$ cd /tmp/opsview_venv/
testing:/tmp/opsview_venv$ source ./bin/activate
(opsview_venv) testing:/tmp/opsview_venv$ python --version
Python 3.9.5
(opsview_venv) testing:/tmp/opsview_venv$ pip install opsview
Collecting opsview
  Downloading opsview-0.9.0.tar.gz (18 kB)
    ERROR: Command errored out with exit status 1:
     command: /tmp/opsview_venv/bin/python -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-ydxw692w/opsview_a347bb61df4f479bb7dece71bd0a1a5d/setup.py'"'"'; __file__='"'"'/tmp/pip-install-ydxw692w/opsview_a347bb61df4f479bb7dece71bd0a1a5d/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-pip-egg-info-io9mw4xi
         cwd: /tmp/pip-install-ydxw692w/opsview_a347bb61df4f479bb7dece71bd0a1a5d/
    Complete output (5 lines):
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-ydxw692w/opsview_a347bb61df4f479bb7dece71bd0a1a5d/setup.py", line 3, in <module>
        from pip.req import parse_requirements
    ModuleNotFoundError: No module named 'pip.req'
    ----------------------------------------