reproduce (this is a W=1 build):
        git checkout linus/master
        b4 shazam https://lore.kernel.org/r/ece4365f-906c-44e2-80c9-ab73f91f7fb5@I-love.SAKURA.ne.jp

        # 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