I’m trying to use code from the official openCV tutorial for showing video from webcam using cv2.imshow() in Ubuntu/Python 3.6: And I get the following error for cv2.imshow(): The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Carbon support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script