Prebuilt Clang 5 libc paths

I am trying to use the prebuilt Clang 5 on Ubuntu 16.04. In the end it fails where Clang seems to not find the c standard library:

clang <…> -nostdinc++ -isystem clang_prebuilt/include/c++/v1

In file included from clang_prebuilt/include/c++/v1/cstdio:100:
In file included from clang_prebuilt/include/c++/v1/stdio.h:108:
In file included from /usr/include/stdio.h:33:
clang_prebuilt/include/c++/v1/stddef.h:18:15: fatal error: ‘stddef.h’ file not found
#include_next <stddef.h>
^~~~~~~~~~

Searching on my system for that header I get:

find /usr -name stddef.h

/usr/include/linux/stddef.h ← empty
/usr/lib/gcc/x86_64-linux-gnu/5/include/stddef.h
/usr/lib/gcc/x86_64-linux-gnu/4.9/include/stddef.h
/usr/lib/gcc/x86_64-linux-gnu/6/include/stddef.h
/usr/lib/gcc/x86_64-linux-gnu/7/include/stddef.h
/usr/src/linux-headers-4.4.0-96/include/linux/stddef.h

/usr/src/linux-headers-4.4.0-96/include/uapi/linux/stddef.h
/usr/src/linux-headers-4.4.0-97/include/linux/stddef.h
/usr/src/linux-headers-4.4.0-97/include/uapi/linux/stddef.h
/usr/src/linux-headers-4.4.0-98/include/linux/stddef.h
/usr/src/linux-headers-4.4.0-98/include/uapi/linux/stddef.h

so I am wondering where stddef.h is supposed to be found on the Ubuntu system?

https://clang.llvm.org/docs/FAQ.html#i-get-errors-about-some-headers-being-missing-stddef-h-stdarg-h

-Eli

Thanks a lot. Had multiple issues in that area but the nudge helped.