It turns out (http://forums.gentoo.org/viewtopic-t-93 ... art-0.html
) that glu lib got split from mesa from upstream. Although I had virtual/glu installed, something must've gone wrong. The command:
# equo install virtual/glu
caused the real package to be installed (it wasn't before), so now I have the file I need back! Hope this saves some time to somebody having the same problem.