pip install error "externally-managed-enviroment"

[kfholland]

I am trying to install Kikit on Ubuntu 24.04. When I issue pip3 install Kikit I get the following error:

error: externally-managed-environment

× This environment is externally managed
╰─> To install Python packages system-wide, try apt install
    python3-xyz, where xyz is the package you are trying to
    install.
    
    If you wish to install a non-Debian-packaged Python package,
    create a virtual environment using python3 -m venv path/to/venv.
    Then use path/to/venv/bin/python and path/to/venv/bin/pip. Make
    sure you have python3-full installed.
    
    If you wish to install a non-Debian packaged Python application,
    it may be easiest to use pipx install xyz, which will manage a
    virtual environment for you. Make sure you have pipx installed.
    
    See /usr/share/doc/python3.12/README.venv for more information.

note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
hint: See PEP 668 for the detailed specification.

There seems to be conflicting suggestions on the internet about how to deal with this so I thought I would ask here. I installed Kicad with the apt, so its not the flatpak.

[yaqwsx]

You can install Python packages via system package manager (in your case apt) or via pip on Linux. The problem is that the way Python import works, packages from these two worlds can import each other and you can easily end up in a situation where packages installed via pip can break packages installed via apt.

Python developers decided to deal with this situation in IMHO really lame way. They introduced the warning you see above and they suggest that you always install pip packages into a virtual environment (with a separate Python interpreter and all the libraries). Which works around the problem (every pip package lives in an isolated universe). However, this conflicts with the needs of KiCAD where plugins have to use the Python interpreter provided by KiCAD (or the system).

I have to do more studying to come up with the cleanest solution possible. In the meantime, the option --break-system-packages is equivalent to the behavior before this change was introduced (and everyone was using KiKit like this since the project started).