title: repo using local manifest does not work
body: <p>Refference to the question <a href="https://stackoverflow.com/questions/5672394/using-a-local-manifest-xml-with-repo">here</a>. 
  I copy the <code>manifest.xml</code> to <code>.repo</code> and type:</p>
  
  <pre><code>repo init -m ./.repo/manifest.xml
  </code></pre>
  
  <p>And it does not work:</p>
  
  <pre><code>jack $ repo init -m ./.repo/manifest.xml 
  fatal: manifest url (-u) is required.
  </code></pre>
  
  <p>I do provide manifest.xml. What is wrong?</p>