toolchain/50980: clang build of netbsd-7 fails (missing c++config.h)

[jan.m.danielsson%gmail.com@localhost]

>Number:         50980
>Category:       toolchain
>Synopsis:       clang build of netbsd-7 fails (missing c++config.h)
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Mar 19 13:05:00 +0000 2016
>Originator:     Jan Danielsson
>Release:        NetBSD/amd64 7.0
>Organization:
La Cosa Nostra
>Environment:
NetBSD testbox.local 7.0 NetBSD 7.0 (GENERIC.201509250726Z) amd64
>Description:
Building netbsd-7 (amd64) using clang causes an error:

-------------------------------
[---]
dependall ===> lib/../external/bsd/libc++
dependall ===> lib/../external/bsd/libc++/include
dependall ===> lib/../external/bsd/libc++/lib
dependall ===> lib/../external/gpl3/gcc/lib/libstdc++-v3
#    create  libstdc++-v3/allocator-inst.d
CC=/home/jan/sysbuild/tools/bin/x86_64--netbsd-clang++ /home/jan/sysbuild/tools/bin/nbmkdep -f allocator-inst.d.tmp  -- -I/home/jan/
sysbuild/dest.amd64/usr/include/g++/backward  -std=c++11 -D_GLIBCXX_ABI_TAG_CXX11=   --sysroot=/home/jan/sysbuild/dest.amd64 -I/usr/
src/external/gpl3/gcc/dist/gcc -I/usr/src/external/gpl3/gcc/dist/include -I/usr/src/external/gpl3/gcc/dist/libstdc++-v3/libsupc++ -I
/usr/src/external/gpl3/gcc/dist/libgcc -I/usr/src/external/gpl3/gcc/lib/libstdc++-v3/../libstdc++-v3/arch/x86_64 -I. -DHAVE_STDLIB_H
 -DHAVE_STRING_H -I/usr/src/external/gpl3/gcc/dist/libstdc++-v3/include -I/usr/src/external/gpl3/gcc/lib/libstdc++-v3/arch/x86_64 -D
_GLIBCXX_SHARED -DGTHREAD_USE_WEAK -DSUPPORTS_WEAK      /usr/src/external/gpl3/gcc/dist/libstdc++-v3/src/c++98/allocator-inst.cc &&  mv allocator-inst.d.tmp allocator-inst.d
In file included from /usr/src/external/gpl3/gcc/dist/libstdc++-v3/src/c++98/allocator-inst.cc:29:
In file included from /home/jan/sysbuild/dest.amd64/usr/include/c++/memory:598:
In file included from /usr/src/external/gpl3/gcc/dist/libstdc++-v3/libsupc++/typeinfo:34:
/usr/src/external/gpl3/gcc/dist/libstdc++-v3/libsupc++/exception:37:10: fatal error: 'bits/c++config.h' file not found
#include <bits/c++config.h>
         ^
1 error generated.
nbmkdep: compile failed.
[---]
-------------------------------

>How-To-Repeat:
On an amd64 system, go to a build directory and set up the environment:

BASE=`pwd`
ARCH=`uname -m`
export TOOLDIR=$BASE/tools
export DESTDIR=$BASE/dest.$ARCH
export RELEASEDIR=$BASE/release
export MAKEOBJDIRPREFIX=$BASE/obj.$ARCH
export MKUNPRIVED=yes

export MKLLVM=yes
export MKLIBCXX=yes
export HAVE_LLVM=yes

In a directory where netbsd-7 is checked out, run:

$ ./build.sh release

>Fix:
Unknown