I have vim build from ports with huge, gtk2 and ruby. The problem is that when I try to add a cscope db it returns an error because vim can't access /usr/bin/cscope.
Of course the cscope port gets installed in /usr/local. Doing a ln -s to /usr/bin/cscope from /usr/local/bin/cscope fixes this, but it's an ugly workaround.