Quite simply, every copy operation needs a call to into() w/o a closure parameter. This is how the base directory get set. Passing a closure parameter creates a child copy spec of the root spec, leaving he base directory of the root spec null. When using the Copy task you get the following error instead of the NPE you get when using Project.copy(). We should fix project.copy so that it gives a similar message.
> No value has been specified for property 'destinationDir'.