I'm trying to emulate a Z-80/Sega Master System game with xmess compiled from pkgsrc, but without success.

xmess give the message that DGA requires root rights. So, as root, I typed:

# xmess -cartridge wboy2.sms -sl sms
XF86DGAQueryExtension failed
Use of DGA-modes is disabled
warning: no mixer plugins available
info: trying to parse: /usr/X11R6/share/xmess/xmessrc
info: trying to parse: /root/.xmess/xmessrc
info: trying to parse: /usr/X11R6/share/xmess/xmess-x11rc
info: trying to parse: /root/.xmess/xmess-x11rc
info: trying to parse: /usr/X11R6/share/xmess/rc/smsrc
info: trying to parse: /root/.xmess/rc/smsrc
Mouse/Trakball selected.
done
Unable to open image file wboy2.sms
Unable to initialize machine emulation
#

The problem is:

"XF86DGAQueryExtension failed"

What's DGA? What can I do to solve this type of problem?

Thank you.