This directory contains sources and breadcrumbs to build jtreg as checked in to jsr166/lib. Peruse ./build-jtreg after exploding the tarball. Somehow JTRegModuleHelper.class did not get included in jtreg.jar. To avoid [jtreg] Cannot find class java/lang/reflect/JTRegModuleHelper.class to init patch directory I hand compiled JTRegModuleHelper.java and updated jtreg.jar javac -d . -cp ../../../jsr166/lib/\* ./src/share/classes/java/lang/reflect/JTRegModuleHelper.java jar uf ../../../jsr166/lib/jtreg.jar java