Pytest not finding serial port within Github Actions

[sethkaz]

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tl;dr. Is there a way to expose a port within the /dev directory to steps being run on a self-hosted runner?

Setup:

• Self-hosted runner (Raspberry Pi 5), with 2 MCUs connected (ESP32S3 and ESP32)
• Repo is an Espressif project
• Repo has actions to lint, build, and test.
• Testing is done using pytest.

I have 2 MCUs connected to the runner because one is the DUT and the other is to act as a mock for various hardware. Because I have 2 MCUs, I want to prevent the situation where the software suite confuses the two devices and crashes out.

To do this, I've created symbolic links (e.g. /dev/hil_links/HIL-Interface) pointing to the appropriate MCU (e.g. /dev/serial/by-id/usb-Silicon_Labs...). This works perfectly when running pytest locally. However, when it is run within Actions, it responds with a [Errno 2] No such file or directory

(Also might be pertinent, I'm running 3 parallel sets of tests. The other two also use the MCUs, and don't have issue accessing the port, so I think it's isolated to pytest settings or the link.)

How I can grant access to the workflow running on the runner to the serial port links?