I'm just wondering about swig dependancies. swig "needs"
  python, perl and tcl in the NetBSD pkgsrc. Actually it
  needs none of those. It could as well be used for developing

If one builds swig without those programs installed, can it then
generate wrappers for them?  If so, the pkg probably shouldn't
buildlink them in.

If swig needs languages at compile time, there probably should be a
SWIG_USE_LANGUAGES variable or something that one can set to choose,
and then we only have to argue about the default :-)

-- 
        Greg Troxel <gdt@ir.bbn.com>