When I invoque catkin_make -DCMAKE_BUILD_TYPE=Release, the compilation fails with this message:
[ 41%] Built target darknet_ros_msgs_generate_messages
[ 43%] Building CXX object vision_opencv/cv_bridge/src/CMakeFiles/cv_bridge_boost.dir/module.cpp.o
[ 44%] Building C object darknet_ros/darknet_ros/CMakeFiles/darknet_ros_lib.dir/__/darknet/src/activation_layer.c.o
[ 44%] Building C object darknet_ros/darknet_ros/CMakeFiles/darknet_ros_lib.dir/src/image_interface.c.o
In file included from /usr/include/opencv4/opencv2/core/types_c.h:82:0,
from /usr/include/opencv4/opencv2/core/core_c.h:48,
from /usr/include/opencv4/opencv2/highgui/highgui_c.h:45,
from /home/chan/catkin_ws/src/darknet_ros/darknet/include/darknet.h:25,
from /home/chan/catkin_ws/src/darknet_ros/darknet/src/box.h:3,
from /home/chan/catkin_ws/src/darknet_ros/darknet/src/image.h:9,
from /home/chan/catkin_ws/src/darknet_ros/darknet_ros/include/darknet_ros/image_interface.h:12,
from /home/chan/catkin_ws/src/darknet_ros/darknet_ros/src/image_interface.c:9:
/usr/include/opencv4/opencv2/core/cvdef.h:690:4: error: #error “OpenCV 4.x+ requires enabled C++11 support”