reproduce (this is a W=1 build):
        git checkout a7bd72158063740212344fad5d99dcef45bc70d6
        b4 shazam https://lore.kernel.org/r/20250822-b4-tcp-ao-md5-rst-finwait2-v1-1-25825d085dcb@arista.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/ipv4/