Excluded artifacts are resolved resulting errors if they're not available

Grails tries to resolve all dependencies - even those that are excluded. In this example, a dependency is being excluded and that excluded dependency isn't available anywhere. Since it's excluded, Grails shouldn't try to retrieve it, yet it does anyways. Since it can't find the dependency, it errors out.

See https://jira.grails.org/browse/GPRELEASE-59
https://groups.google.com/d/msg/grails-dev-discuss/CGFyXd7CgmY/c_J0beqc7rQJ