DGA4132 how to install libubox

what exactly did you do (what were the commands)? what package were you installing and where did it come from? And finally, what is the output of:

ubus call system board

EDIT: Is your device actually running OpenWrt? The DGA4132 is a Technicolor device, right? If so, it's not listed in the table of hardware and according to this thread it will never be supportable by OpenWrt.