title: deriving version numbers from a git repository
body: <p>we have a build system that uses the svn ID as an imput to a VM builder appliance that required a five digit number. When I build from git I have been faking this by counting the number of commits in the git repo. This only sort-of-works :-/ I'm tyring to figure out:</p>
  
  <ul>
  <li>how can I get a unique 5 digit number from the git repo. </li>
  </ul>