title: Why call git branch --unset-upstream to fixup?
body: <p>I'm more of a novice when it comes to advanced operations in git. I maintain my <a href="http://jatinganhotra.com" rel="noreferrer">blog</a> using the blogging framework <a href="http://octopress.org/" rel="noreferrer">Octopress</a>. Though Octopress is not under any development since 2011, it serves my purpose well and so I haven't thought of changing anything so far.</p>
  
  <p>FYI, my blog is hosted on Github Pages.  </p>
  
  <p>Today, while working on a new post, <code>git status</code> showed the following message:</p>
  
  <pre><code>On branch source
  Your branch is based on 'origin/master', but the upstream is gone.
    (use "git branch --unset-upstream" to fixup)
  </code></pre>
  
  <p>The same message repeated for all the subsequent commands such as <code>git add .</code>, <code>git commit -m 'message'</code> and <code>git push origin source</code>.  </p>
  
  <ul>
  <li>What does the message mean?  </li>
  <li>Is something broken?  </li>
  <li>If yes, what?  </li>
  <li>Do I need to fix it? </li>
  </ul>
  
  <p>If possible, please point me to a pdf/web article where I can read up on this and understand it for future.</p>
  
  <p>More details:</p>
  
  <pre><code>bash-3.2$ git branch -a
  * source
    remotes/octopress/2.1
    remotes/octopress/HEAD -&gt; octopress/master
    remotes/octopress/gh-pages
    remotes/octopress/linklog
    remotes/octopress/master
    remotes/octopress/refactor_with_tests
    remotes/octopress/rubygemcli
    remotes/octopress/site
    remotes/origin/source
  </code></pre>
  
  <p>Please let me know if more information is needed. Thanks.</p>