Hi, This patch series adds 'guix system roll-back' and 'guix system switch-generation' commands. It should apply cleanly to the current master branch.
I've tested the patches manually on a VM with a single disk, and a VM with multiple disks (with the store on a separate disk). Two of the "check-system" tests fail (nss-mdns and encrypted-root-os), but those are failing on the current master branch for me anyway, and I can't recall ever seeing them pass, so I have no reason to suspect that my changes are causing the failures. I look forward to your feedback. Thank you, Chris
