reproduce (this is a W=1 build):
        git checkout ffd294d346d185b70e28b1a28abe367bbfe53c04
        b4 shazam https://lore.kernel.org/r/20250129172320.950523-3-tabba@google.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 mm/