title: How does "not something we can merge" arise?
body: <p>This is a new one to me. I'm a fairly experienced user of git, and have just added a remote to a repo that was forked from mine, fetched the updates and then tried to merge them in:</p>
  
  <pre><code>$ git merge HEAD f6ff240dbf47234249a68b34c8a98bb11237aa7
  fatal: f6ff240dbf47234249a68b34c8a98bb11237aa7 - not something we can merge
  </code></pre>
  
  <p>There is next to nothing on the web about this error message, which shocks me.  The nearest thing I can find is <a href="http://micharg.blogspot.co.uk/2012/12/git-troubleshooting-fatal-branch-not.html" rel="noreferrer">this page about being in a detached head state</a>. But <code>git status</code> reports that I am on branch master.</p>
  
  <p>You can see the repositories I am trying to use on github - <a href="https://github.com/aptivate/dye" rel="noreferrer">my repo</a> and the <a href="https://github.com/qris/ping-dye" rel="noreferrer">remote I want to pull from</a>. At the time of writing, master of my repo is at <a href="https://github.com/aptivate/dye/commit/6dc048862a93ffba6cd37883fd43e40651f248c1" rel="noreferrer">6dc048862a93ffba6cd37883fd43e40651f248c1</a>.</p>
  
  <p>Looking at the history I can see where the forks diverge, and I am trying to merge a commit from 3 commits up the fork. It doesn't seem that hard.</p>
  
  <p>To replicate for yourself you could do:</p>
  
  <pre><code>git clone https://github.com/aptivate/dye
  cd dye
  git remote add qris git://github.com/qris/ping-dye.git
  git fetch qris
  git checkout master
  git merge f6ff240dbf47234249a68b34c8a98bb11237aa7
  </code></pre>