=== Attempting to build a kernel with options TCP_SIGNATURE (current DragonFly master) ===
--- config + options registry ---
/usr/src/sys/config/X86_64_GENERIC:19:options 	TCP_SIGNATURE	#DF-2597-test
/usr/src/sys/conf/options:271:TCP_SIGNATURE		opt_inet.h

--- make nativekernel KERNCONF=X86_64_GENERIC result ---
/usr/src/sys/netinet/tcp_output.c:1058:37: error: 'IPSEC_DIR_OUTBOUND' undeclared (first use in this function)
/usr/src/sys/netinet/tcp_output.c:1058:37: note: each undeclared identifier is reported only once for each function it appears in
=== NK_DONE rc=2 ===

--- standalone cc of tcp_subr.c with TCP_SIGNATURE defined ---
tcp_subr.c:2236:9: warning: implicit declaration of function 'key_allocsa'; did you mean 'if_alloc'? [-Wimplicit-function-declaration]
tcp_subr.c:2328:18: warning: implicit declaration of function '_KEYBUF'; did you mean 'PIPE_BUF'? [-Wimplicit-function-declaration]
tcp_subr.c:2328:29: error: dereferencing pointer to incomplete type 'struct secasvar'
tcp_subr.c:2328:42: warning: implicit declaration of function '_KEYLEN' [-Wimplicit-function-declaration]
tcp_subr.c:2330:2: warning: implicit declaration of function 'key_sa_recordxfer' [-Wimplicit-function-declaration]
tcp_subr.c:2331:2: warning: implicit declaration of function 'key_freesav'; did you mean 'kfreeenv'? [-Wimplicit-function-declaration]

--- Does the IPsec SADB subsystem exist in sys/ at all? ---
key_allocsa defined in headers: 0
struct secasvar defined in headers: 0
IPSEC_DIR_OUTBOUND defined anywhere: 0
ipsec directory under netproto: ABSENT