GNU Guix launches

I do actually use debootstrap with chroot sandboxes precisely to be able to manage multiple software environments. However, this only works reliably for genuine chroots and not fakechroots, at least if you want to sample other distribution versions (mostly because of system library incompatibilities), and it gets to the point where you also need a newer kernel version to run significantly newer distribution versions. At that point, I actually use User Mode Linux, but there are plenty of root privilege obstacles that would prevent me from having such a sandbox if I didn't have root access.

Setting up chroot sandboxes isn't really so lightweight, but I suppose it is at the lighter end of the virtualisation spectrum in the broadest sense of the term.