In Python (3.6) API of OpenCV (3.4.2) on Ubuntu 18.10 (kernel 4.15.0-38) I successfully open VideoCapture device and grab frames. At the end, I call the release() method of the VideoCapture instance and get in a shell the error message (no exception is thrown):
VIDIOC_DQBUF: Invalid argument
At the same time, in dmesg I can find entries like:
uvcvideo: Non-zero status (-71) in video completion handler.