How to deal with bugs caused by the rubocop core

[Darhazer]

Recently I've fired a bug report that CountAsOne can lead to negative counts. This one affects RSpec/ExampleLength - which is how I found about it in the first place (well, to be fair, a colleague of mine reported the issue, and I took it from there).

Now that the issue is fixed, and it will be out with the next rubocop release, I have this general question: how we should proceed with it, as it essentially fixes our cops as well.

Should we bump the minimum required version of rubocop, to ensure it counts statements correctly, and release rubocop-rspec with a "fix" for that option?
Should we provide a message that CountAsOne has buggy behaviour for rubocop versions prior to X?
Should we do something else?

[pirj]

bump the minimum required version of rubocop, to ensure it counts statements correctly, and release rubocop-rspec with a "fix" for that option

Without doing such a release, bundle update rubocop-rspec without the --conservative flag would trigger the rubocop update, and the bug would be fixed anyway?
For new projects, the latest version of rubocop with the fix would be bundled as well.