bug#45992: A "live" profile is missing

["Ludovic Courtès" <ludo@gnu.org>]

Leo Famulari <leo@famulari.name> skribis:

> On Mon, Jan 25, 2021 at 07:11:33PM +0100, Ludovic Courtès wrote:
>> What does ‘grep ^localstatedir config.log’ return?
>
> For my "master" and "staging" worktrees, it returns:
> localstatedir='/var'
>
> However, I've since done a full garbage collection and reconfigured, so
> it doesn't really prove anything.

OK.

> --list-live actually starts by printing this:
>
> ------
> $ guix gc --list-live
> finding garbage collector roots...
> skipping invalid root from `/var/guix/profiles/per-user/root/guix-profile-197-link' to `/gnu/store/1ph7vxq4hhqr1hjkmgin16p1cqx3v904-profile'

That means the target of this symlink was already invalid/non-existent,
right?

> And --list-roots does include the bogus profile, exactly as described in
> the warning from --list-live:

OK.

If there’s a root pointing to the profile, and the profile no longer
exists, it could be that the root was created after the profile had been
deleted.  AFAIK that cannot happen in normal operation, so you’d really
have to fiddle with /var/guix/profiles to achieve that.

So… I don’t see how this could happen!

Ludo’.