title: "git describe" ignores a tag
body: <p>In the following lines:</p>
  
  <pre><code>$ git tag -n1
  v1.8        Tagged the day before yesterday
  v1.9        Tagged yesterday
  v2.0        Tagged today
  $ git describe
  v1.9-500-ga6a8c67
  $ 
  </code></pre>
  
  <p>Can anyone explain why the v2.0 tag is not used by "git describe", and how to fix this? The v2.0 tag is already pushed, so I am guessing that I can't just delete and re-add it.</p>