bug#61570: Backward incompatible changes in mpd-service-type

[Liliana Marie Prikler <liliana.prikler@gmail.com>]

Am Montag, dem 06.03.2023 um 20:13 -0500 schrieb Maxim Cournoyer:
> > Am Freitag, dem 17.02.2023 um 07:53 -0500 schrieb Maxim Cournoyer:
> > > Else an error rather than a warning when multiple same-name users
> > > are defined would be more appropriate, I think.
> > Guess what, it used to be a formatted message (i.e. an actual
> > error).  However, that broke some configs as reported in [1], so I
> > demoted it to a warning.
> 
> Interesting.  I didn't know we were usefully (?) abusing duplicate
> users and group.
As far as I'm aware, we aren't.  Even if such uses exist, they raise
said warning and probably cause more issues down the line, like with
your bug report.

> Perhaps we should try to isolate the most common offenders
> (services?), fix them up, and then re-introduce the check, perhaps
> gradually (e.g. "in 6 months time, duplicated users or groups will
> become a configuration error").
The only instance known to me (cups creating a duplicate lp group) was
fixed back in 2021.

Cheers