I'm not familiar with github, I couldn't find more information about it. A mere search of SDL2 obviously returns me 1346 results

with such a name I'm going confused, if its not libSdl related
In the mean time I searched for command lines for Jstest-gtk.
That leads to a composition of a script which shall be more complicated if we integer ffset (force feed-back)
I'll make mine soon and probably post the procedure followed.
Based on
this (french and probably old)
with
that support
A first feed-back on game-play:
I couldn't experiment my 3 axis(turn,roll, strafe and fire in the same time

) manoeuvre yet, but the "feel" seems there

Worst point goes to fps... Add little joystick miss-calibration and the skunk becomes fully uncontrollable if too low...
Not for now that I could strike my beetle alone

On se rend vers la connaissance avec circonspection.
c.a.d, avec un immense respect et la peur au ventre.