[Bug libstdc++/51026] New: Bootstrap failure due to libstdc++ on x86_64-darwin11

[fxcoudert at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51026

             Bug #: 51026
           Summary: Bootstrap failure due to libstdc++ on x86_64-darwin11
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: build
          Severity: blocker
          Priority: P3
         Component: libstdc++
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: fxcoud...@gcc.gnu.org
                CC: amacl...@redhat.com
              Host: x86_64-apple-darwin11
            Target: x86_64-apple-darwin11
             Build: x86_64-apple-darwin11


Bootstrap currently fails on x86_64-apple-darwin11 due to a problem in building
libstdc++.6.dylib:

ld: duplicate symbol std::atomic_thread_fence(std::memory_order) in
.libs/functexcept.o and .libs/compatibility-atomic-c++0x.o for architecture
x86_64
collect2: error: ld returned 1 exit status
make[5]: *** [libstdc++.la] Error 1
make[4]: *** [all-recursive] Error 1
make[3]: *** [all] Error 2
make[2]: *** [all-stage1-target-libstdc++-v3] Error 2
make[1]: *** [stage1-bubble] Error 2
make: *** [all] Error 2