Index: cfe/trunk/runtime/CMakeLists.txt
===================================================================
--- cfe/trunk/runtime/CMakeLists.txt
+++ cfe/trunk/runtime/CMakeLists.txt
@@ -78,6 +78,7 @@
                -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
                -DLLVM_LIBDIR_SUFFIX=${LLVM_LIBDIR_SUFFIX}
                -DCMAKE_OSX_DEPLOYMENT_TARGET=${CMAKE_OSX_DEPLOYMENT_TARGET}
+               -DCMAKE_OSX_SYSROOT:PATH=${CMAKE_OSX_SYSROOT}
                ${COMPILER_RT_PASSTHROUGH_VARIABLES}
     INSTALL_COMMAND ""
     STEP_TARGETS configure build