In its current state this projects builds with Qt's mingw-w64 v11.2.0 binaries, though with some slight tweaks it should be adaptable to any mainstream compiler.
Here are the steps to adapt this project to your compiling environment.

This project's only dependency except for the Qt Framework is Petri Lehtinen's JSON manipulation library. Binaries might already be available for you environment, though we recommend always building open source projects yourself. Read Jansson's build instructions for further details on how to set it up. Once compiled, all you have to do is replace our Jansson build in lib/libs/jansson by you own, and make sure the target_link_libraries command in lib/CMakeLists.txt points to the right static library file.

From here, everything should be set up correctly for compiling the library.
Just generate a project with CMake and build for you desired target.

Once the library has been compiled, replace the files in tester/libs/taskk with your own, then make sure your binary files are linked correctly within tester/CMakeLists.txt (for further details see section 1.). The tester's language can be switched between C and C++ in tester/src/switch.h, just edit the #define USE_CXX 0 line to #define USE_CXX 1 for C++.