title: `git pull` locks up on one repository
body: <p>I have a remote git server that has been working great for months.  Earlier today a couple of my teammates said they were having trouble with <code>git pull</code> for one of our projects.</p>
  
  <p>I am testing it now and I cannot preform a <code>git pull</code> either.  I was able to run <code>git fetch</code> once, but now that isn't working.  When I look at the server processes for the git user (the one that connects to the remote repo) I see 3 processes that are just sitting there: <code>sshd</code>, <code>php</code>, and <code>git-upload-pack</code>.</p>
  
  <p>All of the other repositories that are also on this remote server are working fine.  The repository is fairly large and just had a new branch added to it.</p>
  
  <p>Any ideas on how to fix this?</p>
  
  <p>Thanks.</p>