title: mirroring a git repository is not working
body: <p>I've read a handful of explainations on how to setup a mirror of an upstream and then periodically update the mirror to be up to date with the upstream.  It's not working.</p>
  
  <p>Here is my example:</p>
  
  <h1>Create the mirror from the upstream:</h1>
  
  <pre><code>$ mkdir mirror ; cd mirror
  $ git clone --mirror ssh://git@upstream.host.net:7999/myproject/myrepo.git
  $ cd myrepo.git
  $ git push --all ssh://git@mirror.host.net:7999/myproject/myrepo.git
  $ cd .. ; rm -rf mirror
  </code></pre>
  
  <h1>Make a change occur, upstream:</h1>
  
  <pre><code>$ mkdir upstream; cd upstream
  $ git clone ssh://git@upstream.host.net:7999/myproject/myrepo.git
  $ cd myrepo
  $ git checkout -b newbranch
  $ git push origin newbranch
  $ cd ..; rm -rf upstream
  </code></pre>
  
  <h1>Update the mirror:</h1>
  
  <pre><code>$ mkdir mirror; cd mirror
  $ git clone ssh://git@mirror.host.net:7999/myproject/myrepo.git
  $ cd myrepo
  $ git remote update
  Fetching origin
  $ git branch -a | grep newbranch
  </code></pre>
  
  <pre><code>&lt;nothing&gt;
  </code></pre>
  
  <p>Why doesn't my mirror get newbranch from the update?</p>