Index: trunk/build.xml
===================================================================
--- trunk/build.xml	(revision 10256)
+++ trunk/build.xml	(revision 10257)
@@ -700,4 +700,6 @@
             includeantruntime="false" createMissingPackageInfoClass="false"
             encoding="UTF-8" classpath="${proj-classpath}">
+            <!-- workaround to https://bz.apache.org/bugzilla/show_bug.cgi?id=59556 -->
+            <compilerarg value="-XaddExports:java.base/jdk.internal.reflect=ALL-UNNAMED" compiler="javac1.9" />
         </javac>
     </target>