This issue will appear for Rubocop >= 1.45.0. I tested in roadmap >=3.1.0 version.

Noted in portagenetwork#316, rubocop starts to complain about debugging messages after upgrading to 1.45.1:

It is because rubocop 1.45.0 (rubocop/rubocop#11517) added debugger detection that will affect most of our rake tasks.

Will push the new rubocop.yml soon.