title: git refusing to fetch into current branch
body: <p>I set up a remote repository and I can push new changes to it, but I cannot fetch from it, I always get the (rather cryptic) error message:</p>
  
  <pre><code>fatal: Refusing to fetch into current branch refs/heads/master of non-bare repository
  fatal: The remote end hung up unexpectedly
  </code></pre>
  
  <p>What does it mean? What should I do to enable fetching?</p>
  
  <p>(Note that this remote repo is only used as a backup repo, so it should be pretty much an exact copy of my local repository. I really can't understand why I can push to it but not fetch from it...)</p>
  
  <p>My config looks like:</p>
  
  <pre><code>[remote "origin"]
      url = ssh://blablablah
      fetch = +refs/*:refs/*
      mirror = true
  </code></pre>