Ken Heard composed on 2017-08-04 01:27 (UTC-0400):

I have just installed TDE-Trinity in my Stretch box.  On boot startx

Exactly how did you install it? (moot if anything below solves)

opens x-server-x-org in F7, but the login manager does not appear.
/opt/trinity/bin is in the PATH in /etc/profiles, and tdm-trinity is
installed, but still no login manager. 

Startx is not supposed to open a login manager. It should open a default DE
session, which probably should be TDE in your case.

Surely something else must be necessary to cause the login to appear.  I
looked for guidance in the TDE instructions, but they are anything but
clear.  Can somebody help me out?

Does /etc/X11/default-display-manager exist and contain /opt/trinity/bin/tdm?

What happens if you try

	dpkg-reconfigure tdm-trinity

???

Does

	systemctl status tdm.service

show enabled and on :0 and active? It needs to be if you want TDM's login
manager working.

"What happens if you try

	dpkg-reconfigure tdm-trinity" that was the command I couldn't dig up.

I switched to lightdm and all 3 GUIs work, the problem with the virtual ttys was fixed
switched back to TDM and the problem with trinity returned. so for now, lightdm will work, and remove the anxiety part anyways.