title: TFS build broken - The directory is not empty on sources directory
body: <p>I am having a problem with my build (TFS2010). All has been well with this build recently until today where I am now getting an error pretty much as soon as the build starts:</p>
  
  <pre><code>Delete Sources Directory (00:00) The Directory is not empty.
  </code></pre>
  
  <p>I have looked on the server and I see \builds\1\myproject\sources\ is empty.. there is nothing in there at all! The error hints towards that not being the case, but it is empty for sure.</p>
  
  <p>I wonder if it should not be empty in this case? Can anyone advise me on what course of action I might take on this to get the build running again?</p>
  
  <p>This is the log of the failed build:</p>
  
  <pre><code>Overall Build Process
  00:00
  Update Build Number
  00:00
  Create the Drop Location
  00:03
  Run On Agent (reserved build agent Default Agent - server1)
  00:00
  Delete Test Results Directory
  00:00
  Delete Binaries Directory
  00:00
  Delete Workspace
  00:00
  Delete Sources Directory
   The directory is not empty.
  </code></pre>
  
  <p>Many thanks for any help!</p>