Dear all, I am facing a problem with compiling the ROS sources under Natty. While building the opencv2 package, I got the following linking error: ============================== Linking CXX static library ../../lib/libopencv_haartraining_engine.a [ 80%] Built target opencv_haartraining_engine Scanning dependencies of target opencv_createsamples [ 80%] Building CXX object modules/haartraining/CMakeFiles/opencv_createsamples.dir/createsamples.o Linking CXX executable ../../bin/opencv_createsamples ../../lib/libopencv_highgui.so.2.2.0: undefined reference to `cvCreateCameraCapture_V4L(int)' collect2: ld returned 1 exit status make[2]: *** [bin/opencv_createsamples] Fehler 1 make[1]: *** [modules/haartraining/CMakeFiles/opencv_createsamples.dir/all] Fehler 2 ============================== It seems it has to do with the linking of V4L. I have the lib4vl-dev package installed. According to my prior web search there seems to be the issue that V4L has moved out of the kernel source. Do you have any clues? Cheers, Markus