Currently dev-lisp/common-lisp-controller requires app-misc/realpath, which is blocked by sys-apps/coreutils-8.15. I encounter a conflict message if I pass --with-bdeps=y to emerge -uDN sbcl. The latest revision in the gx86 tree was made for this realpath problem, so please sync.
think I did this the other day when I hit this problem as well Only way I could get rid of the problem was by unmerging realpath, though, bit annoying.