title: openmp in Xcode 4.2
body: <p>I just got the latest Xcode 4.2 and I am running into problems with openmp. I have a couple of projects written in C that compiled without any problem with Xcode 3.2.6 but with the new version strange things happen.
  One of my projects produces a static library and when I compile it I get this error (not a warning):</p>
  
  <pre><code>Lexical or Preprocessor Issue
  'omp.h' not found
  </code></pre>
  
  <p>I have enabled openmp support and selected the LLVM GCC 4.2 compiler. Although I get this error the static library is still generated.</p>
  
  <p>Thinking it could be a conversion problem between 2 different versions of xcode, I created another project with Xcode v4.2 with a simple hello world-like program. I get exactly the same error and the program runs as it should. If I compile this project using the command-line xcodebuild I do not get any error.</p>
  
  <p>Has anyone encountered this problem?</p>