"make buildworld" fails for r360785?

[Robert Huff]

Dimitry Andric writes:
>  >>>> /usr/src/contrib/llvm-project/clang/lib/Basic/SourceManager.cpp:1228:10:
>  >>>> fatal error: 'emmintrin.h' file not found
>  >>>> #include <emmintrin.h>
>  >>>>          ^~~~~~~~~~~~~
>  ...
>  > In file included from /usr/src/contrib/llvm-project/clang/lib/Basic/SourceManager.cpp:1228:
>  > In file included from /usr/include/emmintrin.h:13:
>  > /usr/include/xmmintrin.h:27:10: fatal error: 'mm_malloc.h' file not found
>  > #include <mm_malloc.h>
>  >         ^~~~~~~~~~~~~
>  > 1 error generated.
>  > *** Error code 1
>  
>  During which stage of buildworld is this? If it is during the
>  cross-tools stage, your host environment is busted somehow.

	That is the latest stage listed by the complete build log.
(Which I can make available if it's useful.)
	The only complaint I see is two lines at the top of the log:

make[1]: "/usr/src/Makefile.inc1" line 325: SYSTEM_COMPILER: libclang will be built for bootstrapping a cross-compiler.
make[1]: "/usr/src/Makefile.inc1" line 330: SYSTEM_LINKER: libclang will be built for bootstrapping a cross-linker.

	Makefile.inc1 was downloaded with the fresh source tree, and I
have already posted make.conf and src.conf.
	I am not sure what else could be broken, nor how to diagnose it.

>  This appears to happen to some people on this list, for unknown reasons.
>  My guess is they either run "make delete-old" before running buildworld
>  (which is the wrong order!),

	I did recently run "delete-old" ... but only as directed by the
official documentation.
	But ... let's say that somehow happened.  How do I recover?  Is
there a bootstrap process?  

>						  or have done an earlier buildworld where
>  they explicitly disabled clang, so the intrinsics headers never get
>  installed.

	Other than a custom kernel config file, I don't touch the system
build process.  <insert image of puny human standing before raging
Hulk "Very dangerous - you go first!">



			Respectfully,


				Robert Huff