This is a disassembly of Pokémon Gold (and Silver*) Debug JP.
It builds the following ROM:
MONSGD.gbc (SHA1: 539245e162123ceac77f0615e0eabddd8efb8b7d)
The original build date is the 3rd February 2000, at 21:50 and the ROM was leaked on the 11th April 2020
*Silver TBD