reproduce (this is a W=1 build):
        # https://github.com/morimoto/linux/commit/05fdf1f3b7fc904954b481ffaffd4c8e6d348b3e
        git remote add morimoto https://github.com/morimoto/linux
        git fetch --no-tags morimoto renesas-lts/v6.18.0-2025-12-04-sparrow-hawk
        git checkout 05fdf1f3b7fc904954b481ffaffd4c8e6d348b3e

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash