The Python Dependencies story on SystemCore

[jlmcmchl]

I recently started down the path of compiling https://github.com/SleipnirGroup/Sleipnir/ for Systemcore, and noticed that a lot of utilities that are useful, if not required for python development are not yet included in the image. If on-bot development is in the works for java & python, then users will need these utilities required to build and install dependencies outside the vendordep framework.

Some things I noticed:

• git is present, but https is not a supported protocol for remote repositories. Only ssh is supported.
• pip is not present

Without pip in particular, python is limited to the dependencies in the base image and vendordeps for on-controller development. It would be preferable to enable repo cloning without SSH keys and to include pip from an accessibility standpoint.

[virtuald]

I just got my systemcore HW this week, but won't be starting on RobotPy development for systemcore until next week due to travel. It's likely there will be a lot of things like this -- thanks for this initial list.

[virtuald]

I don't think we'd probably explicitly support building native python packages on systemcore by default though? Just wheels from pypi et al.

[auscompgeek]

The SystemCore image doesn't ship the C toolchain, so the only sdists that could possibly be installed must be pure-Python. So yes, I agree for any native dependencies from PyPI they'd have to be manylinux aarch64 wheels.

[auscompgeek]

I expect we'll be using a virtual environment with a Python build from https://github.com/astral-sh/python-build-standalone, rather than using the system Python 3.11.

The python-build-standalone Linux aarch64 builds now have PGO and BOLT optimisations enabled. I have Python 3.13 running on my SystemCore right now.

[virtuald]

RobotPy 2027.0.0a2 is now available.

[gerth2]

I was poking back here for reasons of making a .ipk that would be able to connect to network tables.

In the python3 that ships with the image, I get a 3.13 repl but it does not show ntcore or other wpilib content.

Is there expected to be a version pre-shipped with SC? Or is the plan for robotpy to continue to install dependencies when the user loads code on?

[auscompgeek]

RobotPy will not be depending on the system Python. Instead we will use an isolated Python environment and target the latest Python version each year.

[virtuald]

There are two twists to this though:

• The RobotPy venv will always be installed to the same place, so your package could just assume that it could use that if it exists... but that seems fraught with problems as its contents could change whenever the user wants (and deploys that change dependencies will recreate the venv)
• They plan to ship systemcore with the blocks programming language, which has a python backend and will generate python code. I think it will ship with it's own venv and cache away the stuff needed for robotpy, so you could go find that and make your own venv or use their packages/venv

With all that said, I think if you're going to go the route of making an installable thing, I would use pyinstaller to create a self-contained executable.