LBANN OS X (#7105)

* Added a package for the MDAnalysis toolkit.

* Added some flags to fix the build RPATHs and OpenMP for LBANN on OS X.

* Fixed Hydrogen branch of Elemental to find OpenMP on OS X.

var/spack/repos/builtin/packages/elemental/package.py

@@ -23,6 +23,7 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import os
+import sys
 from spack import *
 from spack.spec import UnsupportedCompilerError
 
@@ -211,6 +212,15 @@ def cmake_args(self):
             '-DHydrogen_GENERAL_LAPACK_FALLBACK=ON',
         ]
 
+        # Add support for OS X to find OpenMP
+        if (self.spec.satisfies('%clang')):
+            if (sys.platform == 'darwin'):
+                clang = self.compiler.cc
+                clang_bin = os.path.dirname(clang)
+                clang_root = os.path.dirname(clang_bin)
+                args.extend([
+                    '-DOpenMP_DIR={0}'.format(clang_root)])
+
         if 'blas=openblas' in spec:
             args.extend([
                 '-DHydrogen_USE_OpenBLAS:BOOL=%s' % ('blas=openblas' in spec),