Merge pull request #23 in SCALE/spack from features/cmake-prefix-path to develop

# By David Beckingsale
# Via Todd Gamblin
* commit '42ca6c8bfc2b7598acd880a013f7898db5245004':
  Add dependency prefixes to CMAKE_PREFIX_PATH

lib/spack/spack/build_environment.py

@@ -143,6 +143,10 @@ def set_build_environment_variables(pkg):
     os.environ[SPACK_SPEC] = str(pkg.spec)
     os.environ[SPACK_DEBUG_LOG_DIR] = spack.spack_working_dir
 
+    # Add dependencies to CMAKE_PREFIX_PATH
+    dep_prefixes = [d.package.prefix for d in pkg.spec.dependencies.values()]
+    path_set("CMAKE_PREFIX_PATH", dep_prefixes)
+
 
 def set_module_variables_for_package(pkg):
     """Populate the module scope of install() with some useful functions.