[ale] Debian Jessie upgrade startx dead

[agcarver+ale at acarver.net (Alex Carver)]

I just upgraded a laptop from Wheezy to Jessie.  Under Wheezy everything
was fine, I could log in then run startx to bring up the desktop
(fluxbox).  Under Jessie I can't get anything to come up, I just get a
black screen.  Even the virtual terminals are dead (can't Ctrl-Alt-Fn or
crash out with Ctrl-Alt-Backspace).

Nothing seems out of the ordinary, I don't see any obvious error
messages during the startup process.

I'd love suggestions about other places to look for any other issues.
Command line is working, video looks normal there.  I don't think any
configurations changed but I do have a backup of /etc to compare against
but a quick glance says no changes.