You may not have noticed this, but xfree does _not_ have the option for OpenGL, it is mandatory. A glance at the output of `emerge -vp xfree` will confirm this. That means at least one set of libGL and so forth is installed, so it makes sense to install opengl-update (which by the way is a 4KB script). If you'd like to suggest a way to build X without Mesa or any of the 3D drivers, you're welcome to do so. Please reopen the bug if you do.