title: "git diff" does nothing
body: <p>I presume this is a configuration error somewhere, but I can't figure out where.  Regular git commands appear to work fine, but "git diff" does nothing.  To be safe, I removed external diff tools from my .gitconfig file.  This was installed via MacPorts and is the lates version (1.7.2.2).</p>
  
  <p>What I see is that when I run "git diff" from my workspace, it simply exits, doing nothing.</p>
  
  <pre><code>$ git --version
  git version 1.7.2.2
  $ git diff
  $ 
  </code></pre>
  
  <p>If I back up one directory, out of my root workspace, typing "git diff" gives me this:</p>
  
  <pre><code>$ git diff
  usage: git diff [--no-index] &lt;path&gt; &lt;path&gt;
  </code></pre>
  
  <p>This may be expected behavior since I'm not under a git repository.</p>
  
  <p>Any ideas on what I can do to troubleshoot this?</p>