title: specify directory for git pull (not current directory)
body: <p>I'd like to do update my existing checkout from git, but without being inside of that directory:</p>
  
  <pre><code>-sh-3.2$ pwd
  /var/lib/gitolite
  -sh-3.2$ git clone repositories/visits.git/
  Cloning into 'visits'...
  done.
  -sh-3.2$ cd visits/
  -sh-3.2$ git remote -v
  origin  /var/lib/gitolite/repositories/visits.git/ (fetch)
  origin  /var/lib/gitolite/repositories/visits.git/ (push)
  -sh-3.2$ cd
  -sh-3.2$ git --git-dir=/var/lib/gitolite/repositories/visits.git/ --work-tree=/var/lib/gitolite/visits/ pull 
  fatal: No remote repository specified.  Please, specify either a URL or a
  remote name from which new revisions should be fetched.
  -sh-3.2$ cd visits/
  -sh-3.2$ git pull
  Already up-to-date.
  -sh-3.2$ git --version
  git version 1.8.2.1
  -sh-3.2$ 
  </code></pre>
  
  <p>I don't really understand <code>git-dir</code> and <code>work-tree</code>, can someone explain what am I doing wrong?</p>