diff --git a/lldb/CMakeLists.txt b/lldb/CMakeLists.txt
--- a/lldb/CMakeLists.txt
+++ b/lldb/CMakeLists.txt
@@ -111,7 +111,11 @@
           message(WARNING "LLDB test suite requires libc++ in llvm/projects/libcxx or an existing build symlinked to ${cxx_dir}")
         endif()
       else()
-        list(APPEND LLDB_TEST_DEPS cxx)
+        if (NOT TARGET cxx)
+          message(WARNING "LLDB test suite requires libc++")
+        else()
+          list(APPEND LLDB_TEST_DEPS cxx)
+        endif()
       endif()
     endif()
   endif()