from mesa-6.5-r3.ebuild: # Create the two-number versioned libs (.so.#.#), since only .so.# and # .so.#.#.# were made dosym libGLU.so.1.3.060401 /usr/$(get_libdir)/libGLU.so.1.3 but mesa-6.5 installs libGLU.so.1.3.060500.
Fixed, thanks for your patience!