title: CMake cannot find OpenMP
body: <p>I am trying to compile with OpenMP. My <code>CMakeLists.txt</code> contains the line</p>
  
  <p><code>find_package(OpenMP REQUIRED)</code></p>
  
  <p>and CMake errors out with</p>
  
  <pre><code>CMake Error at /opt/ros/groovy/share/catkin/cmake/catkinConfig.cmake:72 (find_package):
    Could not find a configuration file for package openmp.
  
    Set openmp_DIR to the directory containing a CMake configuration file for
    openmp.  The file will have one of the following names:
  
      openmpConfig.cmake
      openmp-config.cmake
  </code></pre>
  
  <p>Checking my filesystem, I see that I have <code>/usr/share/cmake-2.8/Modules/FindOpenMP.cmake</code> but no <code>openmpConfig.cmake</code> or <code>openmp-config.cmake</code>. What do I need to do to fix this?</p>