I'm not a Linux user myself and don't know how to configure joysticks in Linux. Hopefully someone who knows will be able to chime in.
At least on Windows, you want to make sure to not have any other joysticks or special input devices such as wacom tablets connected as that sometimes causes a conflict which makes Freerider unable to recognize your joystick.
After looking through several forums and playing around with python-uinput (allows to software emulate HID stuff like joysticks) I found that this framework needs a joystick that has at least 1 button in order to use it - having 4 axes only is not sufficient!
On top of what framework was this software written? Is this Source Engine? Or UNITY Engine? I noticed that this console text output pattern ("Using libudev for joystick management") is pretty common. If you could tell me that I would open a bug report there.
I'm not sure if you ever found a solution, but thanks to the information you provided about needing at least one button I was able to resolve the same issue for myself.
I used Wejoy (https://github.com/Vantskruv/wejoy) to create a "virtual" joystick with 1 button and 4 axes and just forward the necessary axes from the physical device to the virtual. Hopefully that's useful to you or some future Linux user in need of a fix.
