With the following GDM service:

--8<---------------cut here---------------start------------->8---
(gdm-service-type
 (gdm-configuration
  (default-user "doe")
  (auto-login? #t)))
--8<---------------cut here---------------end--------------->8---

GDM fails to start (nothing happens, nothing is printed in the TTY).

If I set auto-login? to #f, GDM starts properly (but of course does not
log me in automatically).

-- 
Pierre Neidhardt
https://ambrevar.xyz/