reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://github.com/ambarus/linux-0day/commit/7ae3e681354fe887656fe3bc659c697b4e27006a
        git remote add ambarus https://github.com/ambarus/linux-0day
        git fetch --no-tags ambarus v6.12-rc3-acpm-v2
        git checkout 7ae3e681354fe887656fe3bc659c697b4e27006a
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-14.1.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-14.1.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash