title: WiX Heat: Pre-build event fires too early on build server
body: <p>I'm harvesting a directory for my Visual Studio solution.</p>
  
  <p>It works on my local system so far probably because the project build order is being respected.</p>
  
  <p>When I run the installer on a build server it finds the right directory but it has not been created at the time of building the setup file. It throws a <code>HEAT5052</code> error saying <code>The directory 'a:\b\c' could not be found</code>.</p>
  
  <p>Is there any way to "wait" until or to execute the heat command after all project references are built?</p>