title: Git error "fatal: ambiguous argument 'HEAD': unknown revision or path not in the working tree"
body: <p>I'm trying to initialize a new Git repository from <a href="https://en.wikipedia.org/wiki/Debian" rel="noreferrer">Debian</a> (actually a VM on VirtualBox, installed and running on Mac OS X):</p>
  <pre><code>cd ~
  mkdir test
  cd test
  git init
  
  Initialized empty Git repository in /home/david/test/.git/
  fatal: ambiguous argument 'HEAD': unknown revision or path not in the working tree.
  Use '--' to separate paths from revisions
  
  [david@server-VM-001:test  (master #) $]
  </code></pre>
  <p>What's the problem?</p>