Sorry, kind of in a hurry, this might be rushed. Short version: I accidentally commented out my user, reconfigured, realized my mistake, rolled back (logging in was tricky, not sure what made it work), had to add a password again with passwd, got new UID, had to chown -R my $HOME, tried to guix pull --roll-back, but had to chown my /var/run/guix/per-user thing too.