mxcl/homebrew — pull request #8361 by seanlynch (2011-10-29 04:38:21+00:00)
Title: Update Eigen to 3.0.3.

http://eigen.tuxfamily.org/bz/show_bug.cgi?id=338 has been fixed, but
there's not yet a pkgconfig dir under #{prefix}/lib when building, so
we need to set pkg_config_libdir or the .pc file gets installed in
pkg_config_libdir-NOTFOUND.