reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf.git/commit/?id=5559719129b7370573ae4892829ea7c55f702b27
        git remote add netfilter-nf https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf.git
        git fetch --no-tags netfilter-nf testing
        git checkout 5559719129b7370573ae4892829ea7c55f702b27

        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # clang-23 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=$HOME/0day COMPILER=clang-23 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-23 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash net/netfilter/