title: In Adacore's GPR file, how can I set the compiler include search paths for C++
body: <p>I have some C++ code that I need to compile using Adacore GNAT Programming Studio.</p>
  
  <p>One file (<strong>SomeHeader.h</strong>) is in a Common directory (<strong>../../Common/</strong>) relative to my GPR file.</p>
  
  <p>Our convention for C++ include directives is to use</p>
  
  <pre><code>#include "Common/SomeHeader.h"
  </code></pre>
  
  <p>No matter what I do, I cannot get GprBuild to find "Common/SomeHeader.h"
  I followed the instructions here at <a href="https://www.adacore.com/gems/gem-108-gprbuild-and-configuration-files-part-2" rel="nofollow noreferrer">AdaGem 108</a> with modifications for C++</p>
  
  <pre><code>for Include_Switches ("c++") use ("-I ../../");
  </code></pre>
  
  <p>and </p>
  
  <pre><code>for Include_Path ("c++") use "../..";
  </code></pre>
  
  <p>None of this seems to work for me during <strong>gprbuild</strong> and frustratingly I can't seem to get at the backend command that <strong>gprbuild</strong> is using even after turning the build verbosity up.  </p>
  
  <p>I see some temp files in the build messages but they get deleted before I can access them.</p>
  
  <p>I am using Adacore GPS 17.1 on Windows 10  i686-pc-mingw32, GNAT Pro 17.1.</p>
  
  <p>Does anyone know how to get include search paths working in Adacore's <strong>Gprbuild</strong>?</p>