r235510: recent buildworld fail

When compiling world (make buildworld) I receive the bewlo error, which
seems very strange!
The error occured out of the blue on a FreeBSD 10.0-CURRENT/amd64 box.

The line

/usr/obj/usr/src/tmp/usr/bin/ld: Warning: size of symbol
`_ZNSi6ignoreEv_at_GLIBCXX_3.4' changed from 243 in
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so to 211 in
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so

looks like a "mixed up" between CLANG and legacy GCC 4.2.1, as far as I
remember this error was typical for a mismatch.

I can not imagine how this could be introduced on one of my systems.

By the way, all FreeBSD 10.0-CURRENT boxes I have compiling under CLANG
refuse compiling world - neither with make "-jXX buildworld" nor "make
buildworl".

This is my /etc/src.conf:

WITH_CLANG=             YES
WITH_CLANG_EXTRAS=      YES
#
WITH_BIND_LARGE_FILE=   YES
WITH_BIND_SIGCHASE=     YES
WITH_BIND_LIBS=         YES
#
WITH_IDEA=              YES
WITH_HESIOD=            YES
#
WITH_BSD_SORT=          YES
#WITH_BSD_GREP=         YES
#WITH_ICONV=            YES
#
WITH_LIBCPLUSPLUS=      YES
#
#WITH_OFED=             YES
#
PORTS_MODULES=          x11/nvidia-driver
#
MALLOC_PRODUCTION=      YES


What can I do to repair the system?


Regards,
Oliver
[...]
clang++ -O2 -pipe -O2 -fno-strict-aliasing -pipe -O3 -pipe
-fno-strict-aliasing -march=native -Qunused-arguments -fstack-protector
-Wsystem-headers -Wno-empty-body -Wno-string-plus-int
-Wno-tautological-compare -Wno-unused-value -Wno-parentheses-equality
-Wno-unused-function -Wno-conversion -Wno-switch -Wno-switch-enum
-Wno-parentheses -I/usr/src/gnu/usr.bin/gperf/../../../contrib/gperf/lib
-I/usr/src/gnu/usr.bin/gperf  -o gperf bool-array.o hash-table.o input.o
keyword-list.o keyword.o main.o options.o output.o positions.o search.o
version.o getline.o hash.o
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_ifstream<wchar_t, std::char_traits<wchar_t>
>::is_open() const'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_string<wchar_t, std::char_traits<wchar_t>,
std::allocator<wchar_t> >::_Rep::_M_set_length_and_sharable(unsigned long)'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_string<wchar_t, std::char_traits<wchar_t>,
std::allocator<wchar_t> >::_M_check_length(unsigned long, unsigned long,
char const*) const'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_fstream<char, std::char_traits<char>
>::is_open() const'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_istream<wchar_t, std::char_traits<wchar_t>
>::ignore()'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_string<wchar_t, std::char_traits<wchar_t>,
std::allocator<wchar_t> >::_M_copy(wchar_t*, wchar_t const*, unsigned long)'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::string::_M_assign(char*, unsigned long, char)'
/usr/obj/usr/src/tmp/usr/bin/ld: Warning: size of symbol
`_ZNSt13basic_istreamIwSt11char_traitsIwEE6ignoreEv_at_GLIBCXX_3.4' changed
from 243 in /usr/obj/usr/src/tmp/usr/lib/libstdc++.so to 211 in
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_fstream<wchar_t, std::char_traits<wchar_t>
>::is_open() const'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_string<wchar_t, std::char_traits<wchar_t>,
std::allocator<wchar_t> >::_M_move(wchar_t*, wchar_t const*, unsigned long)'
/usr/obj/usr/src/tmp/usr/bin/ld: Warning: size of symbol
`_ZNSbIwSt11char_traitsIwESaIwEE4_Rep26_M_set_length_and_sharableEm_at_GLIBCXX_3.4'
changed from 19 in /usr/obj/usr/src/tmp/usr/lib/libstdc++.so to 24 in
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::string::_M_move(char*, char const*, unsigned long)'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::istream::ignore()'
/usr/obj/usr/src/tmp/usr/bin/ld: Warning: size of symbol
`_ZNKSs15_M_check_lengthEmmPKc_at_GLIBCXX_3.4' changed from 39 in
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so to 36 in
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_ofstream<char, std::char_traits<char>
>::is_open() const'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_string<wchar_t, std::char_traits<wchar_t>,
std::allocator<wchar_t> >::_M_assign(wchar_t*, unsigned long, wchar_t)'
/usr/obj/usr/src/tmp/usr/bin/ld: Warning: size of symbol
`_ZNKSbIwSt11char_traitsIwESaIwEE15_M_check_lengthEmmPKc_at_GLIBCXX_3.4'
changed from 39 in /usr/obj/usr/src/tmp/usr/lib/libstdc++.so to 36 in
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so
/usr/obj/usr/src/tmp/usr/bin/ld: Warning: size of symbol
`_ZNSi6ignoreEv_at_GLIBCXX_3.4' changed from 243 in
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so to 211 in
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_ifstream<char, std::char_traits<char>
>::is_open() const'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::string::_M_copy(char*, char const*, unsigned long)'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::basic_ofstream<wchar_t, std::char_traits<wchar_t>
>::is_open() const'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::string::_M_check_length(unsigned long, unsigned
long, char const*) const'
/usr/obj/usr/src/tmp/usr/lib/libstdc++.so:(*IND*+0x0): multiple
definition of `std::string::_Rep::_M_set_length_and_sharable(unsigned long)'
clang++: error: linker command failed with exit code 1 (use -v to see
invocation)
*** [gperf] Error code 1

Stop in /usr/src/gnu/usr.bin/gperf.
*** [all] Error code 1

Stop in /usr/src/gnu/usr.bin.
*** [all] Error code 1

Stop in /usr/src/gnu.
*** [gnu.all__D] Error code 1

Stop in /usr/src.
*** [everything] Error code 1

Stop in /usr/src.
*** [buildworld] Error code 1

Stop in /usr/src.