robotpkg/image/sift bulk build results

ERROR: This package cannot be built for the following reason: ERROR: ====================================================================== ERROR: No acceptable opencv alternatives could be found ERROR: PREFER_ALTERNATIVE.opencv = opencv3 opencv4 ERROR: ERROR: Suggested value: opencv2 ERROR: ERROR: ====================================================================== make[2]: *** [/local/robotpkg/var/lib/robotpkg/mk/internal/can-be-built-here.mk:221: cbbh] Error 2