reproduce (this is a W=1 build): git remote add nf-next https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next.git git fetch nf-next main git checkout nf-next/main b4 shazam https://lore.kernel.org/r/20260525201116.407338-2-kacper.kokot.44@gmail.com # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 olddefconfig make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash net/netfilter/