--- old/test/jdk/com/sun/tools/jextract/jclang-ffi/TestJextractFFI.java	2018-09-12 21:18:23.000000000 +0530
+++ new/test/jdk/com/sun/tools/jextract/jclang-ffi/TestJextractFFI.java	2018-09-12 21:18:20.000000000 +0530
@@ -110,6 +110,7 @@
                 "-I", clang_header_path.toString(),
                 "-t", "clang",
                 "-d", CLANG_FFI_PATH,
+                "-J-Djextract.debug=true",
                 "-J-Dlibclang.debug=true",
                 "-J-Djava.library.path=" + clang_lib_path.toString(),
                 "-J--module-path", "-J" + CLANG_JAR,