reproduce (this is a W=1 build):
        # https://github.com/zen-kernel/zen-kernel/commit/6601cc3e542564dcbdb6f106745954c866459d9c
        git remote add zen https://github.com/zen-kernel/zen-kernel
        git fetch --no-tags zen 7.1/zen-sauce
        git checkout 6601cc3e542564dcbdb6f106745954c866459d9c

        # 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