Index: llvm/trunk/cmake/modules/LLVMExternalProjectUtils.cmake
===================================================================
--- llvm/trunk/cmake/modules/LLVMExternalProjectUtils.cmake
+++ llvm/trunk/cmake/modules/LLVMExternalProjectUtils.cmake
@@ -147,6 +147,7 @@
                -DLLVM_BINARY_DIR=${PROJECT_BINARY_DIR}
                -DLLVM_CONFIG_PATH=$<TARGET_FILE:llvm-config>
                -DLLVM_ENABLE_WERROR=${LLVM_ENABLE_WERROR}
+               -DLLVM_HOST_TRIPLE=${LLVM_HOST_TRIPLE}
                -DPACKAGE_VERSION=${PACKAGE_VERSION}
                -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
                -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}