Re: guix system delete-generations -- advice?

[Thomas Danckaert]

(I somehow messed up the encoding/body of previous message, so here it
is again. my apologies)

I added `guix system delete-generations' in my git checkout, WIP patch
attached.  I had started to adapt the corresponding code from `guix
package delete-generations', but then realized that
`delete-matching-generations` from (guix scripts package) contains
everything that's needed (could it be moved to (guix ui)?).

One thing I'm not satisfied with is this: `reinstall-grub' does not
reproduce custom grub menu entries added in the (grub-configuration)
section of a system's bootloader configuration.  So users with a
dual-boot system lose theire non-GuixSD grub entries after running
“guix system delete-generations” (until they run “guix system
reconfigure” again).  The existing “guix system switch-generation” has
the same problem.

Is there a way to retrieve the current custom grub entries, other than
providing a system configuration, or, I hardly dare say it out loud,
parsing grub.cfg? How could this be improved?

cheers, Thomas

ps I also noticed that passing an empty string ("") as a command line
argument to many guix commands returns a guile backtrace, e.g. guix
system list-generations "". I find this a little messy, or is it a
feature?