Shared library not found for PyQt5: libxcb-xinerama.so.0 => not found
I'm on Ubuntu 18.04.3 and encountered the same issue. Here is what I resolved this problem.
Uninstall PyQt by using pip3
pip3 uninstall pyqt5
And install it via apt-get
sudo apt-get install python3-pyqt5
The exact same issue occurred when I installed pyqt5 and matplotlib on Ubuntu 20.04, using pipenv (which also creates a venv).
On my system this was easily solved by installing the missing libxcb-xinerama0, using apt:
sudo apt install libxcb-xinerama0