In Groovy 2.5, groovy.util.CliBuilder is a wrapper that delegates to groovy.cli.commons.CliBuilder. However, this wrapper doesn't correctly handle the case when the arguments fail to be parsed.
Here's how it works with the real CliBuilder:
And here's what happens with the wrapper:
I get an object that pretends to be null, but isn't. So I can't determine whether the parsing was successful or not.