opencv global /tmp/pip-req-build-cg56sov1/opencv/modules/videoio/src/cap_v4l.cpp (880) open VIDEOIO(V4L2): can't find camera device code example

Example: global /tmp/pip-req-build-civioau0/opencv/modules/videoio/src/cap_v4l.cpp (587) autosetup_capture_mode_v4l2 VIDEOIO(V4L2:/dev/video0): device is busy

Generally, you can list the available cameras with ls /dev/video* or v4l2-ctl --list-devices