Error compiling custom/generic kernel with FreeBSD 12.1

[Tom Vogt]

Hello,

I'm having problem compiling a custom kernel on my FreeBSD 12.1-p4. I've 
tried to compile GENERIC too. Same error.

I use 
https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig-building.html 
as documentation.

My /etc/make.conf and /etc/src.conf are empty. I've deleted everything 
in /usr/obj/*. Filesystem is UFS for /, /usr/*.

The systems runs under bare metal. Hardware information:
Version: Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
root at gw:~ #  grep memory /var/run/dmesg.boot
real memory  = 17179869184 (16384 MB)
avail memory = 16325709824 (15569 MB)

FreeBSD version:
root at gw:/usr/src # uname -a
FreeBSD gw 12.1-RELEASE-p3 FreeBSD 12.1-RELEASE-p3 GENERIC  amd64

Patchlevel installed:
root at gw:/usr/src # freebsd-version
12.1-RELEASE-p4

FreeBSD SVN Version:
root at gw:/usr/src # svnlite info
Path: .
Working Copy Root Path: /usr/src
URL: https://svn.freebsd.org/base/releng/12.1
Relative URL: ^/releng/12.1
Repository Root: https://svn.freebsd.org/base
Repository UUID: ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Revision: 360286
Node Kind: directory
Schedule: normal
Last Changed Author: gordon
Last Changed Rev: 360151
Last Changed Date: 2020-04-21 15:54:08 +0000 (Di., 21 Apr. 2020)

My kernel include includes:
include GENERIC
ident RACK
makeoptions WITH_EXTRA_TCP_STACKS=1
options TCPHPTS

Command I use to build the kernel:
make buildkernel KERNCONF=RACK

Error:
ctfconvert -L VERSION -g aesni_ccm.o
make[4]: don't know how to make immintrin.h. Stop

make[4]: stopped in /usr/src/sys/modules/aesni
*** Error code 2

Stop.
make[3]: stopped in /usr/src/sys/modules
*** Error code 1

Stop.
make[2]: stopped in /usr/obj/usr/src/amd64.amd64/sys/RACK
*** Error code 1

Stop.
make[1]: stopped in /usr/src
*** Error code 1

Stop.
make: stopped in /usr/src

Any idea whats wrong?

Regards,
Tom