opvp support in ghostscript

[Perry Hutchison]

What do I need to do, to get ghostscript's opvp support to work?

GS works fine displaying to the screen, but when I specify
-sDEVICE=opvp I get

  **** Unable to open the initial device, quitting.

If I also specify -dINITDEBUG=1 to turn on debug output during
gs_init.ps, I get a lot of messages showing progress through
the initialization process -- none of which seem to have anything
to do with device choice, nor to be much different from what
INITDEBUG produces when displaying to the screen -- until

  END FONTS 219 2605656 1227805 1417680 125870 true 1166 4 <0>
  Unrecoverable error: unknownerror in setdevice
  Operand stack:
      --nostringval--

which is not a whole lot more informative than the original message.
(When displaying to the screen, which works, the next line after
"END FONTS ..." is "END DEVICE ...")

Is there any way to turn on debug or tracing, or otherwise get more
detail, re what is going on in setdevice and exactly what failed?

This is with the 8.3-RELEASE package of Ghostscript 9.05.