If you want to tinker with the gnubg code or just test out the latest changes on windows, the batch file here will build gnubg from scratch on windows:
https://drive.google.com/file/d/1-52afhxiZGv2Nzt9AhFFTw_WrdNIemjZ/view?usp=drive_link
I've updated it to use the new git repository. Just run the batch file and it should take about 10 minutes to complete.
You can then edit the code by running "MSYS2 MINGW32" from the start menu and the code will be in the gnubg subdirectory. e.g,
$ cd gnubg
$ nano gtkgame.c
$ make
$ ./gnubg
Alternatively the code can be found directly in windows, in C:\msys64\home\<user>\gnubg.
Jon