reproduce (this is a W=1 build):
        # https://github.com/isilence/linux/commit/9852e159a9d1e771fe98518bf7f67ac9ee145203
        git remote add isilence https://github.com/isilence/linux
        git fetch --no-tags isilence zcrx/v10-wip
        git checkout 9852e159a9d1e771fe98518bf7f67ac9ee145203
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash net/core/ net/ipv4/