// https://stackoverflow.com/questions/30994628/why-does-xgrabkey-return-badrequest
 
uses
xlib,
keysym,
x;
 
var
d :  PXDisplay;
root : TWindow;
keycode, rv : Int64;
evt : TXEvent;
 
begin
d := XOpenDisplay(nil);
root := DefaultRootWindow(d);
keycode := XKeysymToKeycode(d, XK_BackSpace);
 
rv := XGrabKey(d, keycode, AnyModifier, root, 1, GrabModeAsync, GrabModeAsync);
writeln('XGrabKey returned');
writeln(rv);
 
    while true do begin
        XNextEvent(d, @evt);
        writeln('Got event');
        writeln(evt._type);
    end;
end.