I'd like my Debian 10 box with vanilla GNOME to prompt for login at a tty/text terminal instead of having the gdm GUI pop up by default. Is there a way to change some config such that it works like this, and then the GNOME interface can be started manually with e.g.
Well I think you want to use multi-user.target target. Systemd uses targets where Sysv / init system uses runlevels. So basically what you need to do is. 1) Check your current target using
This will most probably return graphical.target. Now you can change this by running
systemctl set-default multi-user.target && reboot
Or, without the need to reboot your system, you'd run
systemctl isolate multi-user.target
to force an immediate switch to the textual interface