title: How to building a rpm from multiple projects
body: <p>I know how to build rpm for its own project, however I am not sure what is the proper way to build a rpm that depend on multiple projects to be build first. For example, say I have project A, B, C, D, and FINAL.</p>
  
  <ul>
  <li>B needs A</li>
  <li>C needs A</li>
  <li>D needs B and C</li>
  <li>FINAL needs D</li>
  </ul>
  
  <p>So if i am to make rpm for <code>FINAL</code>, what would be the proper way to trigger the other projects to build? </p>
  
  <ul>
  <li>Make a shell script that trigger the calls and call it under <code>%build</code>?</li>
  <li>In the Makefile of <code>FINAL</code> </li>
  </ul>