Comment # 16 on bug 1089287 from Fabian Vogt

I tried to debug this further, the issue is that sddm doesn't actually create a
session and set a controlling tty. That's currently done by the X server.
This explains why -keeptty does not work and also why loginctl doesn't show
vt7.

sddm only calls setsid for the user session, but as there's no X server in the
user session it doesn't get a controlling terminal either.

While looking at lightdm to check how it's done properly I noticed that it has
the exact same issue.

What does sddm need to do to work with -keeptty?