In the current FX 9 build, the Java packager module delivers a jar files with utility classes used by the packager (packager.jar) and an "ant" plugin (ant-javafx.jar). The contents of both of these jar files is missing from the FX jake build. The packager classes should be delivered as part of the "java.packager" module (currently named "javafx.pacakger" but that needs to change). The ant-javafx.jar file will need to continue to be delivered as a jar file.