Hy all, I think I found a workaround to my linking problem. Editing the manifest.xml of opencv2, I noticed that it exports its libraries as -lopencv_. Back in the CMakelist file of ladybug2, I replaced the occurrences of "cv" and "highgui" respectively by "opencv_core" and "opencv_highgui". And this solved my compilation problem. Still, the warning about SDL stays present and I'd like to remove it. Also, I would like to see clear in this and understand if my problem(s) come(s) from a wrongly installed system or ROS, outdated packages (ladybug2 is part of the semi stable trunk of the sail repository), or something else. If anyone has an input, I'd be glad to hear about it. Raphael -- View this message in context: http://ros-users.122217.n3.nabble.com/problem-compiling-ladybug2-tp2027702p2033905.html Sent from the ROS-Users mailing list archive at Nabble.com.