$ LIBGL_DEBUG=verbose glxgears
libGL: OpenDriver: trying /usr/lib/powerpc-linux-gnu/dri/tls/nouveau_dri.so
libGL: OpenDriver: trying /usr/lib/powerpc-linux-gnu/dri/nouveau_dri.so
libGL: driver does not expose __driDriverGetExtensions_nouveau(): /usr/lib/powerpc-linux-gnu/dri/nouveau_dri.so: undefined symbol: __driDriverGetExtensions_nouveau
libGL error: failed to load driver: nouveau
libGL: OpenDriver: trying /usr/lib/powerpc-linux-gnu/dri/tls/swrast_dri.so
libGL: OpenDriver: trying /usr/lib/powerpc-linux-gnu/dri/swrast_dri.so
libGL error: failed to load driver: swrast
Error: couldn't get an RGB, Double-buffered visual