New addon configuration dynamic lib

Hello

I want to create a new addon that use ftdi2xx so i have to link a dynamic library.

In my addon_config i put the following

ADDON_LDFLAGS = -lftd2xx

But i dont see the flag -lftd2xx when compiling… seems like is ignoring the flag.

What im doing wrong? im on ubuntu and qtcreator4.6.1