DISPLAY wasn't set ("echo $DISPLAY" just prints an empty line) and with (In
reply to comment #14)
> Make sure the DISPLAY environment variable is not set, and set the
> environment variable EGL_LOG_LEVEL=debug to get more information.

DISPLAY wasn't set ("echo $DISPLAY" just prints an empty line) and with
"EGL_LOG_LEVEL=debug es2gears_screen" I get:
    libEGL debug: Native platform type: x11 (build-time configuration)
    libEGL debug: EGL search path is /usr/lib64/egl
    libEGL debug: added egl_dri2 to module array
    libEGL warning: DRI2: xcb_connect failed
    libEGL warning: DRI2: xcb_connect failed
    libEGL debug: EGL user error 0x3001 (EGL_NOT_INITIALIZED) in eglInitialize

    EGLUT: failed to initialize EGL display

/usr/lib64/egl doesn't exist ... but I'm not sure what should be there or if
that is the cause for xcb_connect failing. Any idea what I could do ?