Not sure. I tried to update the core but couldn't get it to work (see https://groups.google.com/forum/#!topic/job-dsl-plugin/9li8Cqd7ENc)

I can add a ticket for this. Would it go towards the job-dsl plugin or the gradle-jpi plugin?

BTW I noticed a reference to the same issue here: https://github.com/jenkinsci/job-dsl-plugin/blob/master/job-dsl-plugin/src/test/groovy/javaposse/jobdsl/plugin/SeedJobTest.groovy#L13