title: Eclipse CDT/Qt: have a Qt Gui project depend on another C++ project in the workspace
body: <p>I've implemented a rather complex algorithm in an Eclipse C++ project ("MyAlgorithm") using Eclipse/CDT. In order to be able to visualise the steps of the algorithm, I'd like to create a simple Qt GUI. I've downloaded and installed the Qt Eclipse integration and have created a Qt Project ("MyGUI") with a main window. Everything compiles like it should - the individual components are all in place.</p>
  
  <p>However, when I try to use the classes from MyAlgorithm in MyGUI, everything grinds to a stop... Although I've referenced MyAlgorithm in MyGUI in all possible dialogs and places I can think of [1], building the project still fails with:</p>
  
  <blockquote>
    <p>main.cpp:5: fatal error: MyAlgorithmClass.h: No such file or directory</p>
  </blockquote>
  
  <p>List of places where I've referenced MyAlgorithm in MyGUI (all in the project properties of "MyGUI"):</p>
  
  <ul>
  <li>C/C++ Include Paths and Symbols (using "Add Include Path from Workspace...")</li>
  <li>C/C++ Project Paths (tab "Projects", checked the "MyAlgorithm" project in list "Required projects on the build path"</li>
  <li>Project References, checked the "MyAlgorithm" project in list "Project references for 'MyGUI'"</li>
  </ul>
  
  <p>Although the build process fails, the Eclipse/CDT auto-complete feature <em>does</em> suggest the existence of "MyAlgorithmClass.h" when I try to include it in the "MyGUI" project. I also noticed that changing the project settings (as described in the list above) does not trigger any changes in the Makefile.</p>
  
  <p>Might it be the case that the Qt Eclipse integration prevents CDT from updating the Makefile accordingly, causing the build process to fail because of missing parameters to the compiler/linker?</p>
  
  <p>Thanks for your help!</p>