One difference between your build and mine was that I installed the port
"esound" (which supplies ESD). Gnubg will use ESD for sound if ./configure
finds it installed. I noticed your build output suggests you have no sound
support. Although I installed esound after everything when I run gnu sound
output puts this on the console "unsupported device". Something I'll have to
look at, but I did notice there is an "ESD" variant in macports. You might
want to try esound on your build and see what happens.