title: What goes wrong when using git worktree with git submodules
body: <p>I recently discovered the <a href="https://git-scm.com/docs/git-worktree"><code>git worktree</code></a> command:</p>
  
  <blockquote>
    <p>The new working directory is linked to the current repository, sharing everything except working directory specific files such as HEAD, index, etc.</p>
  </blockquote>
  
  <p>But the docs also indicate </p>
  
  <blockquote>
    <p>… the support for submodules is incomplete. It is NOT recommended to make multiple checkouts of a superproject.</p>
  </blockquote>
  
  <p>without further explanation as to what goes wrong.</p>
  
  <p>Can someone enlighten me about the problems to expect? For example, will I be fine if I use the separate worktrees generated this way only for changes that do not affect the submodules?</p>