title: Unable to use pipenv to install: ImportError: cannot import name 'InstallRequirement' from 'pip_shims.shims'
body: <p>Since a few hours I had issues with installing dependencies via pipenv. I decided to recreate my environment again and start from scratch, using a different python version (3.8.9). I'm now unable to even install any packages at all, and retrieve the following traceback:</p>
  <pre><code>  File &quot;/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pipenv/vendor/requirementslib/models/requirements.py&quot;, line 18, in &lt;module&gt;
      from pip_shims.shims import (
  ImportError: cannot import name 'InstallRequirement' from 'pip_shims.shims' (unknown location)
  </code></pre>
  <p>Any ideas how to resolve this?</p>