This extension has some specific features for the English Wikipedia.
Note: This extension should be checked out in the folder named "huggle" in your huggle3-qt-lx repo.
You need to build the Huggle core library first. Once you complete that, open the .pro file and ensure the include path is pointing to the folder with Huggle's source code. All of Huggle's header files can be included. Copy the Huggle core library to the src folder of the extension.
Now, try to build it. The .dll file it produces needs to be copied to extensions folder.
Make sure that the include folder points to the huggle folder. Next, build the library and copy the .so file to the proper extensions path.