I tried to port wxmaxima; it failed because I already had maxima installed (/usr/local/bin/maxima). Now the obvious solution would be to also use macports to install maxima. In fact, I did try this a couple of months ago, only to see it fail because it could not install the dependency sbcl. At the time, I just gave up on macports, installed sbcl and then maxima from the source. This worked out fine. Probably, I can do the same with wxmaxima.