batocera-linux/batocera.linux ? reverse-engineered prompt

I want you to get this Batocera project building for me so I can make a bootable retro gaming system image for a USB stick or SD card. Please use what is already in the repo and take the simplest path to a real result, ideally one common target like a normal PC first, instead of trying to cover every board or device at once.

Set up whatever is needed, fix obvious build issues, and leave me with a clean working flow that produces the final image file. I also want simple notes on how to run the build, where the output ends up, and which config files I would edit later if I want to change platforms or included emulator related packages.

Do not reinvent the project or make a separate app. I want this repo itself turned into something I can actually build and use as a console style OS that runs from removable media without changing the main computer. If anything is unclear, check the current Batocera docs and wiki online and follow the existing project conventions.