No matter what it's too leaky an abstraction. Everything in the stdlib uses require. Every fundamental piece of ruby code not in the stdlib uses require. The process of getting from point A to point C involves crossing a point B so frustrating, limiting, and ugly no one is really willing to cross it.

Ruby's global constant namespace was probably a mistake in hindsight, but at this point it'd be a language fork to change it meaningfully.

I was wondering how you could achieve the same level of isolation in ruby, this looks like a very interesting project. Ruby projects move fast and even though they're pretty good about semantic versioning this isn't enough to save you when your Gemfile starts filling up. Cargo looks like a huge improvement over require.