--- jsr166/build.xml	2018/05/08 19:46:11	1.270
+++ jsr166/build.xml	2018/05/15 22:36:42	1.271
@@ -1433,6 +1433,7 @@
            fork="true">
 
       <include name="**/*.java"/>
+      <compilerarg value="-J--illegal-access=debug"/>
       <compilerarg value="-XDcompilePolicy=simple"/>
       <compilerarg line="-processorpath ${errorprone.jar}"/>
       <compilerarg value="-Xplugin:ErrorProne