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/wsa/linux.git/commit/?id=7f3a9d0a8f9131103c2a0a3c92bff3acde93be1b
        git remote add wsa https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git
        git fetch --no-tags wsa wdt/no-register-err
        git checkout 7f3a9d0a8f9131103c2a0a3c92bff3acde93be1b
        # 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 drivers/watchdog/