reproduce (this is a W=1 build):
        git remote add pcmoore-audit https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit.git
        git fetch pcmoore-audit next
        git checkout pcmoore-audit/next
        b4 shazam https://lore.kernel.org/r/cfafc5247fbfcd2561de16bcff67c1afd5676c9e.1761918165.git.rrobaina@redhat.com

        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        # clang-22 might not be officially released. Try a lower version if installation fails.
        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=$HOME/0day COMPILER=clang-22 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-22 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash net/netfilter/