bug#68384: TTY Auto-login is not compatible with elogind

[Lars Rustand]

Enabling both TTY auto-login and elogind-service-type at the same time
results in an error immediately after automatic login to the tty with
the message "Error in service module", and the TTY then is
frozen. Auto-login works fine if I disable elogind, but elogind is
unfortunately a crucial part of the Guix system since a lot of things
does not work without it.

Below is attached a minimal example, simply commenting out the elogind
service in this example makes it works as expected. Running it as is
will result in the error I mentioned.


(use-modules
  (gnu)
  (gnu services)
  (gnu services base)
  (gnu services desktop)
  (gnu bootloader)
  (gnu bootloader grub)
  (gnu system)
  (gnu system file-systems)
  (gnu system accounts)
  (gnu system locale))

(operating-system
  (host-name "minimal")

  (users
    (cons*
      (user-account
        (name "lars")
        (group "users"))
      %base-user-accounts))

  (services
   (cons*
    (service elogind-service-type)
    (modify-services %base-services
      (mingetty-service-type config =>
                             (mingetty-configuration
                              (inherit config)
                              (auto-login "lars"))))))

   (bootloader
     (bootloader-configuration
       (bootloader grub-efi-bootloader)
       (targets '("/boot/efi"))))

   (file-systems
    (cons*
     %base-file-systems)))