This is from the dev-list: http://marc.info/?t=138869346100002&r=1&w=2 When using a doclet, destdir is optional and with Ant 1.9.3 an exception occurs. A possible workaround is setting postProcessGeneratedJavadocs to false. The error generated by Ant 1.9.3: BUILD FAILED java.lang.NullPointerException at org.apache.tools.ant.taskdefs.Javadoc.postProcessGeneratedJavadocs(Javadoc.java:2450) at org.apache.tools.ant.taskdefs.Javadoc.execute(Javadoc.java:1790) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292) at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.Target.execute(Target.java:435) at org.apache.tools.ant.Target.performTasks(Target.java:456) at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1393) at org.apache.tools.ant.Project.executeTarget(Project.java:1364) at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41) at org.apache.tools.ant.Project.executeTargets(Project.java:1248) at org.apache.tools.ant.Main.runBuild(Main.java:851) at org.apache.tools.ant.Main.startAnt(Main.java:235) at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280) at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)
fixed with svn revision 1555019