None of the .so files installed by cogl link with libGLU. cogl might include a GLU header or something? I'll do more investigation tomorrow with more sleep.
It's not sufficient to test whether a package's .so libraries link to something. For example, cogl does not link to libGL; instead, it opens it at runtime via g_module_open (glib's wrapper for dlopen). However, you are right about cogl and glu. It turns out that cogl bundles a large chunk of libGLU tesselator source code with some private modifications, and therefore it neither links to nor dlopens the systemwide libGLU library. + 19 Jan 2013; Alexandre Rostovtsev <tetromino@gentoo.org> + -cogl-1.12.0-r1.ebuild, -files/cogl-1.12.0-fix-experimental-doc-build.patch, + cogl-1.12.2.ebuild: + Remove unneeded glu dependency (bug #452912, thanks to Matt Turner). Drop + old.
