After I booted to a Guix install USB, chrooted as described on the
Arch wiki and started a Guix daemon, I could reconfigure as before.
There was no need to fiddle with grub-install.

After multiple reconfigures, it happened again, my /etc/shadow has !
again in the password field.  My recently changed root password became
empty as well, like 35902.  I did not even run sudo concurrently.  The
password just got locked.

The /etc from the “populating from /gnu/store/*-etc” messages has no
significant differences either.



On Sat, Jun 01, 2019 at 11:37:51PM +0200, Ludovic Courtès wrote:
> "pelzflorian (Florian Pelz)" <pelzflorian@pelzflorian.de> skribis:
> > AccountsService appears to only be usable for reading /etc/shadow, not
> > for writing it, contrary to what the Guix manual claims (??). 
> 
> That might be a bug.
> 

AccountsService obviously can change passwords.  No bug here.  Sorry.
I was confused.


> > For writing passwords, gnome-control-center does not use
> > AccountsService, it calls /usr/bin/passwd directly in its source code
> > in panels/user-accounts/run-passwd.c.
> 
> That’s definitely a bug to fix: it should invoke
> /run/setuid-programs/passwd instead.
>

Find attached two patches that fix GNOME password changing.  Both are
required.

Regards,
Florian