title: omp.h not found, OS X Yosemite not using newest gcc version
body: <p>I am trying to build GraphChi on OS X Yosemite but get the following error:</p>
  
  <p><code>fatal error: 'omp.h' file not found</code></p>
  
  <p>From this question - <a href="https://stackoverflow.com/questions/25990296/how-to-include-omp-h-in-os-x">How to include omp.h in OS X?</a> - I learned that Yosemite uses Clang instead of gcc, which does not include omp.h.</p>
  
  <pre><code>$ which gcc
  /usr/bin/gcc
  $ gcc -v
  Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
  Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn)
  Target: x86_64-apple-darwin14.1.0
  Thread model: posix
  </code></pre>
  
  <p>Next, I installed gcc via Homebrew</p>
  
  <pre><code>$ brew info gcc
  gcc: stable 4.9.2 (bottled)
  http://gcc.gnu.org
  /usr/local/Cellar/gcc/4.9.2_1 (1092 files, 177M)
  Built from source with: --without-multilib
  </code></pre>
  
  <p>and updated <code>$PATH</code> to include the path to the new gcc version</p>
  
  <pre><code>$ echo $PATH
  /usr/local/Cellar/gcc/4.9.2_1:usr/local/bin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin
  </code></pre>
  
  <p>however, <code>gcc -v</code> and <code>which gcc</code> still point to the old version, and building GraphChi still doesn't work due to the missing omp.h file</p>
  
  <p>Does anyone know what else I need to do?</p>
  
  <p><strong>Update</strong></p>
  
  <p><code>locate omp.h</code> returned: </p>
  
  <pre><code>/usr/local/Cellar/apple-gcc42/4.2.1-5666.3/lib/gcc/i686-apple-darwin11/4.2.1/include/omp.h
  /usr/local/Cellar/gcc/4.9.2_1/lib/gcc/4.9/gcc/x86_64-apple-darwin14.1.0/4.9.2/include/omp.h
  /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/gcc/x86_64-apple-darwin13.0.0/4.8.2/include/omp.h
  </code></pre>
  
  <p>my <code>~/.profile</code>: </p>
  
  <pre><code>export PATH=/usr/local/Cellar/gcc/4.9.2_1/lib/gcc/4.9/gcc/x86_64-apple-darwin14.1.0/4.9.2/include:/usr/local/Cellar/gcc/4.9.2_1/bin:usr/local/bin:/opt/local/bin:/opt/local/sbin:$PATH
  </code></pre>