libnat | Libraries for NAT traversal and hole punching

Got it solved.

This was a combination of stuff that was happening and it may differ from project to project. There are different reasons of why this could be happening, but all of them has to do with the Daemons that get spin up when gradle does it's job.

But long story short, what worked for me was to:

Open Activity Monitor (Task Manager on Windows), check for any Java processes and terminate them.

Then I would run again the command ./gradlew bundleRelease or ./gradlew assembleRelease.

I have also read that these Daemons after some time (couple hours I guess) would stop by themselves.

After days on the issue, the problem was related to the include files.

Because I am doing a cross compilation for Android, I haven't done the "make install" step. That makes no sens to install the package on my dev machine. Thus, I just grab the .a files from the compilation folder and the include files from the sources.

Here was my mistake !

The include files that I have to put with the compiled libraries are only a subset of all the files found on the src/include folder... sounds obvious afterwards...

Thus I had to specify a temporary CMAKE_INSTALL_PREFIX and run make install. Then grab the include folder from that location.

Then everything works as expected.

Turns out, as mentioned by Michael, that the test environment doesn't support the loading of a native library. I tested the same code by sending it to a phone bundled in an app and it worked fine.
Therefore in this case, the unit testing cannot be used to test the library unfortunately.

Native libraries are not placed in /data/data/your.app but in /data/app/your.aapp-==/lib/, for example on my target:

Got it to work by loading the pretrained model locally instead of from the hub.

You can't use native static libraries directly in Android apps.

Android user space is basically a Java (or more precisely Dalvik VM). So all user-facing applications must be written in Java or Kotlin (which both compile to Dalvik bytecode).

Static C/C++ libraries must be link in to a C/C++ executable or dynamic library to be used. They can not be loaded directly by Linux or Android.

Since Android app does not have a C/C++ executable in it, the only way to use a static library with an Android app is to link it with a dynamic library (*.so) that can be loaded via Java Native Interface.

Since JNI uses the system loader to load the library, it can only load dynamic libraries, and of those, only ones that export functions with proper naming conventions so they can be matched to a Java class that will be used to call the native code.

Apparently, when a function name is indicated, it might mean that the stack of that function overflowed. I added the static keyword to some arrays inside vcode_synth_frame_rate, and that SIGSEGV error disappeared.

I still did not understand this very well, if anyone has more detailed information please add an answer and I'll mark it as the accepted answer.

Your native-lib library fails during linking because you haven't told it where to find the definitions for get_hello(). You need to link the library containing the definition of get_hello() to the native-lib library.

Your code has this line:

What I did to get std::filesystem to work was changing the solution platform to x64 instead of the default Win32.

I did this on Visual Studio, in a console application.

However, I hope this could be helpful.