Haven't looked at any changes around that recently, but my understanding is - if you add you hornetq jar (the one containing the missing classes) to the JBOSS_HOME/client folder (through AS_TRUNK/build/build.xml) then the rest of the build process automagically adds your jar to the ClassPath attribute of jbossall-client.jar. In short, the ClassPath attribute of jbossall-client.jar is autogenerated.