Fixes <https://issues.guix.gnu.org/63198>.
Have the CUPS service extend pam-root-service-type providing minimal
configuration to authenticate users. Since PAM authentication is provided,
the regular cups package can be used as default instead of the minimal,
PAM-lacking variant.
* gnu/services/cups.scm (cups-configuration)
[cups]: Replace cups-minimal with cups.
[allow-empty-password?]: PAM service configuration permitting empty passwords.
(opaque-cups-configuration): Likewise.
(cups-pam-service): New procedure.
(cups-service-type): Extend pam-root-service-type with cups-pam-service.
Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>
e02584b456