HAOS is not meant to allow access to install other things in the OS. If you do want OS control on the device running HA, you will need to use another installation method, such as container. That will mean you cannot use addons but need to do everything in containers.
The other option would mean running HAOS in a VM, but I don’t think you can do that on a rpi4.
Could it be those tools you need are already installed in the addon? They might not need to be installed on the bare os.
Thanks for the reply. I run HA in containers in some other installations, but I would like use Hass OS in the powerboat setup, just for simplicity. I more and more start to enjoy the pure simplicity and stability of Hass OS.
If I add the necessary binaries and tools to the container, will the container be able to enable/reach the can0 device? I mean, the hat is physically attached to the RPi and I guess the RPi needs to recognize the device to even present it to the addon container, right?
Yeah, I currently run SignalK on a separate RPi, and I will probably continue to do so. But I still wonder if the can tools in a container potentially/in theory could reach the Pican-M hat if attached to a Hass OS RPi.