bug#45830: Assert, that user and group names are unique -> breaks guix system reconfigure

[Leo Prikler <leo.prikler@student.tugraz.at>]

Hello again,
Am Mittwoch, den 13.01.2021, 00:23 +0100 schrieb Leo Prikler:
> Hi Jonathan,
> 
> Am Mittwoch, den 13.01.2021, 00:03 +0100 schrieb Jonathan Brielmaier:
> > Hi Leo,
> > 
> > your commit a3002104:
> > system: Assert, that user and group names are unique.
> > 
> > breaks `guix system reconfigure` for me and other people (at least
> > two
> > in IRC).
> > 
> > $ guix system reconfigure config.scm
> > guix system: error: the following groups appear more than once: lp
> > 
> > $ sudo grep lp /etc/group
> > lp:x:989:
> > 
> > lpadmin:x:975:
> > 
> > $ sudo grep lp /etc/passwd
> > lp:!:18467::::::
> It would seem you have two or more services adding an lp group then. 
> Or one service and a manually defined one.
> 
> > The same happend on my server with the `nginx` group.
> Same problem here; you're probably adding an nginx group twice in
> some
> way.  This is especially concerning, given that it's groups twice –
> for
> some reason nothing is adding additional users or else that check
> would
> have been triggered first.
> 
> > I reverted it for the mean time, as I find it pretty grave...
> I would have preferred, if you could instead have demoted it to a
> warning.  I understand, that stuff suddenly breaking can be
> frustrating, but I doubt the configurations you're using are fine.
> 
> > ~Jonathan
> Regards,
> Leo
I've re-applied the patch with errors demoted to warnings.  I hope you
and the other people, who've reported this in IRC will be able to
figure out where the duplicate groups come from.

Regards,
Leo