I'm trying to use GNOME Shell on my Allwinner A33 tablet (as I have already get Mali binary driver (a EGL-X11/GLES only driver) to work).

Any other clutter programs works well with COGL_DRIVER=gles2, however, mutter cannot work, and exits with "Cannot initialize driver" (I forgot the precise error).

After hours of debugging, I found a problem:

In src/backends/x11/meta-renderer-x11.c:50 get_x11_cogl_winsys_vtable(), it will judges whether it's a wayland compositor...

However, with a X11-only EGL, it is impossible to be a compositor, so it called _cogl_winsys_glx_get_vtable, which is ridiculous for GLES situation (EGL should be used instead).

After commenting out the if, and directly call _cogl_winsys_egl_xlib_get_vtable, it works.