title: python@3.9: the bottle needs the Apple Command Line Tools to be installed
body: <p>I have zsh and Python 3.9 installed on my MacOS but whenever I try to try something in the command line, I'm getting this kind of error:</p>
  <pre><code>brew install python@3.7  # for example
  </code></pre>
  <blockquote>
  <p>Error: python@3.7: the bottle needs the Apple Command Line Tools to be
  installed.</p>
  </blockquote>
  <p>Help would be appreciated.</p>