Hi,

Following codes can be found from file configure.ac:

    drm)
        test "x$enable_gbm" = "xno" &&
                AC_MSG_ERROR([EGL platform drm needs gbm])
        DEFINES="$DEFINES -DHAVE_DRM_PLATFORM"
        ;;

It doesn't make sense, if enable_gbm is "no", then should output the error message and stop auto-configuring

So, it seems it should be modified as:
    drm)
        if test "x$enable_gbm" = "xno"; then
                AC_MSG_ERROR([EGL platform drm needs gbm])
        fi
        DEFINES="$DEFINES -DHAVE_DRM_PLATFORM"
        ;;

If I'm right, I'd like to commit a patch to fix it

Thanks