On actions that run against ruby-dev, it currently prints the following output ([example workflow](https://github.com/rubocop/rubocop/actions/runs/19435093163/job/55603747044)): > Using Bundler 2 shipped with ruby-head But ruby-head ships with bundler 4. There is also the following deprecation from bundler: > [DEPRECATED] Using the `config` command without a subcommand [list, get, set, unset] is deprecated and will be removed in the future. Use `bundle config set --local path /home/runner/work/rubocop/rubocop/vendor/bundle` instead. There is a bit of code to handle bundler 1/2 for a variety of different configurations already, so I won't open a PR for this. It's a bit too complicated to really understand what is going on for me