The RC1 release of gradle, with its change to the test classpath, has broken the GWT unit test framework. Deep inside the GWT framework, it uses the URLClassloader when searching for resources and classes for testing. In the RC1 release notes, it suggests to check the classpath in the manifest of the jar it generates, but this cannot be easily done without rewriting large parts of the GWT test framework. I imaging this change could cause various problems in other frameworks as well, as it is a bit non-standard.

Perhaps an alternative to the current jar manifest approach would be to copy the jars to a directory, and then use a wildcard for the classpath (e.g. java -cp mydir/*)? This would only work with JDK 1.6 however. How does Ant handle this problem?