# pip3 install opencv-contrib-python-headless
import cv2
cap = cv2.VideoCapture('cv2-crash.mkv')
while True:
    ret, frame = cap.read()
    if not ret:
        break
    cap_time = cap.get(cv2.CAP_PROP_POS_MSEC)
    print( cap_time )
cap.release()

[...]
163992.0
Core Dump (Segmentation fault)