reproduce (this is a W=1 build):
        # https://github.com/alobakin/linux/commit/cb251653bf74723c653ae96a5b5a97e57dcc7b18
        git remote add alobakin https://github.com/alobakin/linux
        git fetch --no-tags alobakin libeth
        git checkout cb251653bf74723c653ae96a5b5a97e57dcc7b18

        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash