Index: head/math/darknet/Makefile
===================================================================
--- head/math/darknet/Makefile	(revision 513916)
+++ head/math/darknet/Makefile	(revision 513917)
@@ -1,36 +1,49 @@
 # $FreeBSD$
 
 PORTNAME=	darknet
 PORTVERSION=	g20180914
+PORTREVISION=	1
 PORTEPOCH=	1
 CATEGORIES=	math
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Open source neural networks in C
 
 LICENSE=	PD
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 USES=		gmake
 USE_GITHUB=	yes
 GH_ACCOUNT=	pjreddie
 GH_TAGNAME=	61c9d02
 USE_LDCONFIG=	yes
 
-MAKE_ARGS=	OPTS=-O3
+MAKE_ARGS=	OPTS=-O3 CC=${CC} CPP=${CXX}
 
-BINARY_ALIAS=	gcc=${CC} g++=${CXX}
-
 PLIST_FILES=	bin/darknet \
 		include/darknet.h \
 		lib/libdarknet.a \
 		lib/libdarknet.so
+
+OPTIONS_DEFINE=		OPENCV OPENMP
+OPTIONS_DEFAULT=	OPENCV OPENMP
+# Many secondary functions in DarkNet depend on OpenCV which is a large dependency.
+# Build with OPENCV=off for a self-contained executable which would support
+# core NN computations but would not support many visualization, training and
+# other features.
+
+OPENCV_USES=	pkgconfig
+OPENCV_MAKE_ARGS=	OPENCV=1
+OPENCV_LIB_DEPENDS=	libopencv_video.so:graphics/opencv \
+			libopencv_core.so:graphics/opencv-core
+
+OPENMP_MAKE_ARGS=	OPENMP=1
 
 do-install:
 	${INSTALL_PROGRAM} ${WRKSRC}/darknet ${STAGEDIR}${PREFIX}/bin
 	cd ${WRKSRC} && ${COPYTREE_SHARE} include ${STAGEDIR}${PREFIX}
 	${INSTALL_DATA} ${WRKSRC}/libdarknet.so ${STAGEDIR}${PREFIX}/lib
 	${INSTALL_DATA} ${WRKSRC}/libdarknet.a ${STAGEDIR}${PREFIX}/lib
 	${STRIP_CMD} ${STAGEDIR}${PREFIX}/lib/libdarknet.so
 
 .include <bsd.port.mk>