Daniel confirmed privately he rebuilt velocity locally. The pom.xml file in velocity has a dependency on ant with the scope 'provided'. The recent versions of maven-debian-helper no longer inject this kind of dependencies in the package dependencies (because the provided dependencies are usually satisfied at runtime by a container. This is typical with the dependencies on the Servlet and the OSGi APIs). So here the rebuilt velocity package lacks the dependency on ant and breaks jarjar-maven-plugin.
Thank you for spotting this issue Daniel. I'm going to add the missing build dependency on Ant. __ This is the maintainer address of Debian's Java team <http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/pkg-java-maintainers>. Please use debian-j...@lists.debian.org for discussions and questions.