RaspiOS (bookworm, 64bit) fails to install PyQt5 via Pip

[ullix]

On both my Raspi4 and Raspi5 with OS bookworm, I cannot pip-install PyQt5. About a dozen other Python modules were installed successfully, only PyQt5 failed.

I created a venv and activated it, then from within the venv I did a pip installation with command 'python -m pip install -U pyqt5'. The error-output ended with:

'× Encountered error while generating package metadata.'

See attached file for full output.

I believe something is missing in the build instructions, maybe only in Raspi OS, or already in Debian. Build instructions here: https://www.riverbankcomputing.com/static/Docs/PyQt5/installation.html#building-and-installing-from-source

I used the default OS install:
Raspberry Pi OS with desktop
    Release date: December 5th 2023
    System: 64-bit
    Kernel version: 6.1
    Debian version: 12 (bookworm)