YARN-9487. NodeManager native build shouldn't link against librt on macOS. Contributed by Siyao Meng.

Signed-off-by: Wei-Chiu Chuang <weichiu@apache.org>
(cherry picked from commit 6e4399ea61eb4301f4b6c59633d77c0a04efb12b)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/CMakeLists.txt

@@ -188,5 +188,10 @@ add_executable(test-oom-listener
         main/native/oom-listener/impl/oom_listener.h
         main/native/oom-listener/test/oom_listener_test_main.cc
 )
-target_link_libraries(test-oom-listener gtest rt)
+if(CMAKE_SYSTEM_NAME MATCHES "Darwin")
+    # macOS doesn't have librt
+    target_link_libraries(test-oom-listener gtest)
+else()
+    target_link_libraries(test-oom-listener gtest rt)
+endif()
 output_directory(test-oom-listener test)