title: How do I compare the state of remote Mercurial repositories?
body: <p>I have a repo forked on BitBucket:</p>
  
  <pre><code>$ hg paths
  default = https://bitbucket.org/mine/project
  upstream = https://bitbucket.org/theirs/project
  </code></pre>
  
  <p>Now I want to compare the (local) state of my repo with its upstream.  Using git I'd just write <code>git diff --stat upstream/master origin/master</code> but hg doesn't appear to accept remote branch names as an argument:</p>
  
  <pre><code>$ hg diff --stat upstream/default default/default
  default/default: No such file or directory
  upstream/default: No such file or directory
  </code></pre>
  
  <p>I'm guessing I could probably specify it as a <a href="http://www.selenic.com/hg/help/revsets" rel="nofollow noreferrer">revset</a>, but I'm having trouble getting the syntax right and can't find any examples.</p>
  
  <p>The question <a href="https://stackoverflow.com/questions/6877748/mercurial-compare-local-and-remote-repositories">Mercurial - compare local and remote repositories?</a> appears related but that just shows the differences between local and remote state; I want to see the difference between remote state and the upstream remote it is forked from.</p>