The ebuild for gnocatan (games-board/gnocatan) requires glib 2.x for building. However, the RDEPENDS attribute only lists "dev-libs/glib" (i.e., without a specific version requirement). If only glib 1.x is installed on a system, the build process will fail at configure time. So the dependency should be ">=dev-libs/glib-2.0" instead of "dev-libs/glib".
Fixed in CVS. Thanks!