--- old/src/java.base/share/classes/jdk/internal/loader/BootLoader.java	Tue Mar  8 21:59:15 2016
+++ new/src/java.base/share/classes/jdk/internal/loader/BootLoader.java	Tue Mar  8 21:59:15 2016
@@ -224,7 +224,7 @@
                 // named module from runtime image or exploded module
                 Optional<Module> om = BOOT_LAYER.findModule(moduleName);
                 if (!om.isPresent())
-                    throw new InternalError();
+                    throw new InternalError("Module not present:" + moduleName);
                 return om.get();
             }