reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://github.com/cilium/linux/commit/b63a4fd5ab6dc77dd8544abfd6e5d057754e6bc8
        git remote add cilium https://github.com/cilium/linux.git
        git fetch --no-tags cilium max/vxlan-bigtcp
        git checkout b63a4fd5ab6dc77dd8544abfd6e5d057754e6bc8
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=i386 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/net/ethernet/mellanox/mlx4/