title: Relative paths for include files in Eclipse CDT
body: <p>Structure is this:</p>
  
  <pre><code>subsystem
    sub_dir
    sub_dir
    ...
    new_sub_dir_for _unit_test_which_includes_eclipse_workspace 
       Debug       &lt;===   this, I think, being  ${workspace_loc} 
                          or is the parent directory ${workspace_loc}?
                          (since it contains .project and  .cproject)
       test_cases
       stubs
    file_1.c
    file_1.h
    file_1.c
    file_1.h
    ...
    software_under_test.c
    software_under_test.h
  </code></pre>
  
  <p><code>software_under_test.c</code> says <code>#include "../somefile.h"</code>, which is obviously outside of this subsystem.</p>
  
  <p>When I am setting up my include path with <code>Properties/C &amp; C++ general/paths and symbols</code>, I can't seem to use a relative path, only an absolute, which I do not want to do, as I want others to be able to build this project on their machines and the start of the path can vary per user.</p>
  
  <p>I did try adding <code>${workspace_loc}../</code> and variations thereof, but I can't get it work.</p>
  
  <p>What am I doing wrongly?</p>