reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://git.kernel.org/pub/scm/linux/kernel/git/melver/linux.git/commit/?id=0030818ee37e806a78ceb9e303142eafe34a2a80
        git remote add melver https://git.kernel.org/pub/scm/linux/kernel/git/melver/linux.git
        git fetch --no-tags melver cap-analysis
        git checkout 0030818ee37e806a78ceb9e303142eafe34a2a80
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-14.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-14.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash