apt-get environment variables for Emacspeak?

[Rich Morin <rdm@xxxxxxxxxxx>]

I'm having trouble using the 'apt-get install emacspeak' in an automated
fashion.  Partway through the execution of this command, it puts up a
"Package configuration" dialog which wants to know the default speech server.

I read that I can pre-set this by setting the environment variable DTK_PROGRAM,
but I'm not sure which option would be appropriate for my use case (Emacspeak
running in a VirtualBox VM), nor how the option should be specified.

My take, FWIW, is that "a speech server on another computer" seems plausible,
in that the user will be accessing Emacspeak over SSH (and Vagrant).  However,
I could also imagine a user wanting to use eSpeak, Orca, etc.  (e.g., because
they like its user interface or VoiceOver can't handle high generation rates)

Getting Emacspeak working on Perkify is a high priority for me, so suggestions
and comments would be greatly appreciated.

-r

P.S.

I'm also concerned that there may be more settings lurking in the wings, so if
there is a document that describes these, I'd love to know about it.