Cinterop not linking

I have 2 folders, libs/ containing .so files and include/ containing roc.h. The instructions from the library maker are:

Add /path/to/ROC_SDK/include to your include directories and /path/to/ROC_SDK/lib to your lib directories. #include <roc.h> and link against roc.

Now, my attempt to create a .def is:

headers = roc.h
package = roc

All the .so files weights around 100MB, while the output .klib is 35KB. I can see the generated headers and the IDEA autocompletition correctly works on those but of course when compiling:

import roc.roc_version_minor

fun main(args: Array<String>) {
> Task :runProgram FAILED
> Task :compileKonanNrtLinux_x64 FAILED
/tmp/konan_temp2815748691342882954/combined.o:ld-temp.o:function roc_kniBridge1: error: undefined reference to 'roc_version_minor'
error: /home/lamberto/.konan/dependencies/target-gcc-toolchain-3-linux-x86-64/x86_64-unknown-linux-gnu/bin/ invocation reported errors