> Sounds a bit like how Homebrew works (or used to, anyway).

It's not by accident! In its original docs, Homebrew described itself as package management "the GoboLinux way".

Given how Homebrew has become this super-popular tool, its success makes me proud of Gobo's legacy (and a bit vindicated from all the people who told us "this model is crazy, it will never be usable!" :) )

> keeping all versions of everything is that you end up with problems when you're trying to build/use packages with a large pool of dependencies

Yes, it can be a pain! In recent years, we introduced Runner (https://gobolinux.org/runner.html) in GoboLinux as a way to address this kind of issue; a virtualization layer to present the expected dependencies at the right places.