title: CMake remove include directory
body: <p>Is there any way to remove once found include directory in CMake. I found similar question <a href="https://www.mail-archive.com/cmake@cmake.org/msg06396.html" rel="noreferrer">here</a>. But answer does not make much sense for me.</p>
  
  <p>I need almost exactly same as author of the above mentioned message. I have a global CMakeLists.txt file which finds all neccessary include paths. However in CMakeLists.txt file of a one particular submodule, I want to "hide" or "remove" system include path and provide alternative include path.   </p>
  
  <p>Yes, one solution could be just simply change includes in the mentioned submodule, but this submodule is an external library from other repository, so I do not want to change its code.   </p>