TaskRunner splits arguments by space before it adds them back to the vargs list, so it loses all context of quote escaped strings with embedded spaces. This gets fixed up later by wrapping all arguments with " – so you get something like java "-D<opt>=<value>". This is problematic for paths with embedded spaces, where we end up creating "-D<opt>=<first part" "last part>". To java, the jar being run is last part. So with the environment above, you will see "ClassNoDefFoundError: memorable" and the jar will fail to start. In this particular case, we know that java.libarary.path contains paths and the tests often use %PATH% to seed this, so the fix is to remove embedded quotes in listed path elements because we know the aggregate will be quoted when the JVM is started.