diff --git a/openmp/runtime/cmake/LibompCheckFortranFlag.cmake b/openmp/runtime/cmake/LibompCheckFortranFlag.cmake
--- a/openmp/runtime/cmake/LibompCheckFortranFlag.cmake
+++ b/openmp/runtime/cmake/LibompCheckFortranFlag.cmake
@@ -19,7 +19,9 @@
            print *, \"Hello World!\"
       end program hello")
 
-    set(failed_regexes "[Ee]rror;[Uu]nknown;[Ss]kipping")
+    # Compiling as a part of runtimes introduces ARCH-unknown-linux-gnu as a
+    # part of a working directory.  So adding a guard for unknown.
+    set(failed_regexes "[Ee]rror;[Uu]nknown[^-];[Ss]kipping")
     include(CheckFortranSourceCompiles)
     check_fortran_source_compiles("${fortran_source}" ${boolean} FAIL_REGEX "${failed_regexes}")
     set(${boolean} ${${boolean}} PARENT_SCOPE)
diff --git a/openmp/runtime/cmake/LibompCheckLinkerFlag.cmake b/openmp/runtime/cmake/LibompCheckLinkerFlag.cmake
--- a/openmp/runtime/cmake/LibompCheckLinkerFlag.cmake
+++ b/openmp/runtime/cmake/LibompCheckLinkerFlag.cmake
@@ -21,7 +21,9 @@
      project(foo C)
      set(CMAKE_SHARED_LINKER_FLAGS \"${flag}\")
      add_library(foo SHARED src_to_link.c)")
-  set(failed_regexes "[Ee]rror;[Uu]nknown;[Ss]kipping;LINK : warning")
+  # Compiling as a part of runtimes introduces ARCH-unknown-linux-gnu as a part
+  # of a working directory.  So adding a guard for unknown.
+  set(failed_regexes "[Ee]rror;[Uu]nknown[^-];[Ss]kipping;LINK : warning")
   set(base_dir ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/link_flag_check_${boolean})
   file(MAKE_DIRECTORY ${base_dir})
   file(MAKE_DIRECTORY ${base_dir}/build)