I’ve been squinting at the “global cache for all bundler instances” issue[1] and I’m trying to figure out if it’s a minefield of hidden complication or if it’s actually relatively straight forward.

It’s interesting as a target because it pays off more the longer it has been implemented as it only would be shared from versions going forward.

[1] https://github.com/ruby/rubygems/issues/7249

It's definitely not super straightforward, but there's plenty of recent prior art to steal from. Ruby was probably not the best place to solve this for the first time given the constraints (similar to pip), but there's no reason the Ruby ecosystem shouldn't now benefit from the work other ecosystems have done to solve it.