reproduce (this is a W=1 build):
        git checkout 4941a17751c99e17422be743c02c923ad706f888
        b4 shazam https://lore.kernel.org/r/20251127013908.66118-3-fengnanchang@gmail.com

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