Bundler should give a better error when the Gemfile itself activates a conflicting gem

I have been running into a strange situation which I believe is due to differing versions of the built-in gem set in different docker images.

My application runs on ruby 3.0.6 currently. My CI is CircleCI, and I use the cimg/ruby:3.0.6-browsers which appears to use set:1.0.3 However my devops team is running my application on Docker, using ruby:3.0.6alpine3.16 which appears to use set:1.0.1

Whichever of those versions I specify in Gemfile.lock will cause an error similar to this:

`check_for_activated_spec!': You have already activated set 1.0.1, but your Gemfile requires set 1.0.3. Since set is a default gem, you can either remove your dependency on it or try updating to a newer version of bundler that supports set as a default gem. (Gem::LoadError)

Similar things have happened to me on other projects that use more up-to-date versions of ruby.

I would have expected that bundler would be able to force the use of the version of the gem in Gemfile.lock, it hadn't occurred to me that I would need to inspect which versions were built-in to my images.

No source file or test is named. Reproduce the activated-gem conflict with the Ruby 3.0.6 Docker images, Gemfile, and Gemfile.lock described in the report, then trace the Bundler error entry point; done means the conflict produces a clearer error for this case.