Can't change key bindings

on linux mint 19, source built without a hitch, used steam version data
game boots great, no stuttering no slowdown

but I cant rebind the controls
whats going on? am I doing something wrong?

glad I could get a timely reply

avp is a small open source project, unfortunately with a small community it is difficult to expect a fast reply. The more people write about this project here the more likely people are to come by who have knowledge about that project.