reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/kas/linux.git/commit/?id=935c04c0d8b3d599e0af395373911e60d113a3d9
        git remote add kas https://git.kernel.org/pub/scm/linux/kernel/git/kas/linux.git
        git fetch --no-tags kas compound_head
        git checkout 935c04c0d8b3d599e0af395373911e60d113a3d9

        # 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 mm/