ERROR: ERROR: Could not find a version that matches black
No versions found
Was <redacted> reachable?
[pipenv.exceptions.ResolutionFailure]:       req_dir=requirements_dir
[pipenv.exceptions.ResolutionFailure]:   File "/usr/local/.pyenv/versions/2.7.16/lib/python2.7/site-packages/pipenv/utils.py", line 726, in resolve_deps
[pipenv.exceptions.ResolutionFailure]:       req_dir=req_dir,
[pipenv.exceptions.ResolutionFailure]:   File "/usr/local/.pyenv/versions/2.7.16/lib/python2.7/site-packages/pipenv/utils.py", line 480, in actually_resolve_deps
[pipenv.exceptions.ResolutionFailure]:       resolved_tree = resolver.resolve()
[pipenv.exceptions.ResolutionFailure]:   File "/usr/local/.pyenv/versions/2.7.16/lib/python2.7/site-packages/pipenv/utils.py", line 395, in resolve
[pipenv.exceptions.ResolutionFailure]:       raise ResolutionFailure(message=str(e))
[pipenv.exceptions.ResolutionFailure]:       ResolutionFailure: ERROR: ERROR: Could not find a version that matches black
[pipenv.exceptions.ResolutionFailure]:       No versions found
[pipenv.exceptions.ResolutionFailure]: Warning: Your dependencies could not be resolved. You likely have a mismatch in your sub-dependencies.
  First try clearing your dependency cache with $ pipenv lock --clear, then try the original command again.
 Alternatively, you can use $ pipenv install --skip-lock to bypass this mechanism, then run $ pipenv graph to inspect the situation.
  Hint: try $ pipenv lock --pre if it is a pre-release dependency.
ERROR: ERROR: Could not find a version that matches black
No versions found
Was <redacted> reachable?

['Traceback (most recent call last):\n', '  File "/usr/local/.pyenv/versions/2.7.16/lib/python2.7/site-packages/pipenv/utils.py", line 501, in create_spinner\n    yield sp\n', '  File "/usr/local/.pyenv/versions/2.7.16/lib/python2.7/site-packages/pipenv/utils.py", line 649, in venv_resolve_deps\n    c = resolve(cmd, sp)\n', '  File "/usr/local/.pyenv/versions/2.7.16/lib/python2.7/site-packages/pipenv/utils.py", line 539, in resolve\n    sys.exit(c.return_code)\n', 'SystemExit: 1\n']