[civodul]

"guix describe" and "guix time-machine" make it rather easy to pin a Guix revision (and thus the whole package set) and to restore it anytime:

https://guix.gnu.org/manual/en/html_node/Replicating-Guix.ht...

[pxc]

I really like the design of `guix time-machine`. It's pretty cool how it just reuses the existing syntax for other subcommands, instead of modifying them.