Error compiling stable/11 from stable/10

[Matt Smith]

Hi, I'm attempting to compile the latest stable/11 from a 12 day old 
stable/10 system and I'm getting the following error. I've tried 
completely deleting /usr/obj. I've tried without make -j. And I've tried 
commenting out options from src.conf and make.conf and nothing seems to 
make any difference. Any ideas? I haven't tried it yet but I'm wondering 
if I should do RC2 before stable/11.

In file included from 
/usr/src/lib/liblzma/../../contrib/xz/src/liblzma/lz/lz_encoder.c:
23:
/usr/src/lib/liblzma/../../contrib/xz/src/liblzma/common/memcmplen.h:19:11: 
fatal error:

      'immintrin.h' file not found
      #       include <immintrin.h>
		      ^
		      1 error generated.
		      *** Error code 1

		      Stop.
		      bmake[4]: stopped in /usr/src/lib/liblzma



-- 
Matt