GeckoDB is an implementation of a GDB Server which uses a USBGecko to debug Wii/Gamecube games. It requires a debugger payload to be loaded into the game's memory.
To have access to the USBGecko through the FTD2XX driver, you need to follow the procedure at https://docs.rs/libftd2xx/0.32.4/libftd2xx/#udev-rules