In my build.xml I specified to use java 8 like this: use -help for a list of possible options javac: invalid target release: 1.8.0_111 When I compile it against Java 8 I get this error: Compiling 542 source files to /usr/share/feedxl-deploy/temp/FeedXLWebapp/HibernateUpdate/build/classes I am on Ubuntu 14.04 LTS, I installed Java 8 as described here: