I want to install OpenCV on a Python3.6.6 Virtual Environment on Raspberry Pi 4. Have tried a lot of methods how to do it but none of them work. So basically I have raspberry pi 4, have created a virtual environment of python 3.6.6, trying to install OpenCV but about 10 ways do not work. The message “Installing build dependencies…” is taking forever, about at least 3 hours, and no change at all? Is there any way that I can download any version of OpenCV in this case? For the python3.6.6 I have installed the Gripped source tarball straight from the terminal.