Building with the attached random configuration file,

warning: (NF_TABLES_INET) selects NF_TABLES_IPV6 which has unmet
direct dependencies (NET && INET && IPV6 && NETFILTER && NF_TABLES)
warning: (NF_TABLES_INET) selects NF_TABLES_IPV6 which has unmet
direct dependencies (NET && INET && IPV6 && NETFILTER && NF_TABLES)

  LD      init/built-in.o
net/built-in.o: In function `nft_reject_eval':
nft_reject.c:(.text+0x67bc1): undefined reference to `nf_ip6_checksum'
nft_reject.c:(.text+0x67c28): undefined reference to `ip6_route_output'
nft_reject.c:(.text+0x67d09): undefined reference to `ip6_dst_hoplimit'
make: *** [vmlinux] Error 1