I've just run into a slight bug in the Ant jacoco:coverage task. If I am using a "junit" task as part of the "jacoco:coverage" task, it won't take a value for "fork" other than the literal string "true". If I use a property that's set to "true", it gives me this error:
D:\workdir\local-tc-common-all\build.xml:158: The following error occurred while executing this line:
D:\workdir\local-tc-common-all\ivy.dir\ivy.tasks.xml:116: Coverage can only be applied on a forked VM
I've verified this on Stackoverflow, here's a link to the bug: http://stackoverflow.com/a/12052843/368630
I've would have put this issue directly into your bug tracker, but couldn't find that.
Thank you for reporting this! I opened an issue for this:
Fixed on trunk. Please re-test with the latest trunk build.