maxima 5.38.0 with sbcl (at least) does not install maxima.core in the library directory (it is not listed in the PLIST either). To get it working, I had to:
mkdir -p /usr/pkg/lib/maxima/5.38.0/binary-sbcl
tar cf - . | ( cd /usr/pkg/lib/maxima/5.38.0/binary-sbcl ; tar xvf - )
(/usr/pkg/bin/maxima still is incorret, containing as a fallback location
With the above both xmaxima and wxmaxima work - 6 tests failed out of 10,614 total tests.