Hi, this post belongs to the thread <url:http://lists.boost.org/MailArchives/boost/msg76063.php> but I don't have that thread in my local archive anymore. I face the same problem as Curtis Spencer did. Linking an application built with g++ 3.4.3 against boost_serialization-gcc-mt produces warnings from the linker: g++ -pthread -g -O2 -pthread -o testsuite-LaRed testsuite-LaRed.o ReductionTestdata.o testcase-Testdata.o testcase-Matrix.o testcase-GS.o testcase-LLL.o testcase-BKZ.o testcase-RSR.o -L/home/cludwig/Cxx/gcc3.4/LaRed-0.1-BUILD/src /home/cludwig/Cxx/gcc3.4/LaRed-0.1-BUILD/src/.libs/liblared_ntl.a /home/cludwig/Cxx/gcc3.4/LaRed-0.1-BUILD/src/.libs/liblared.a -lboost_unit_test_framework-gcc-mt -lboost_serialization-gcc-mt -lboost_filesystem-gcc-mt -L/home/cludwig/Cxx/gcc3.4/usr/lib/ -lntl /usr/lib/libgmp.a `.gnu.linkonce.t._ZNK5boost7archive17archive_exception4whatEv' referenced in section `.rodata' of /home/cludwig/Cxx/gcc3.4/usr/lib//libboost_serialization-gcc-mt.a(basic_iarchive.o): defined in discarded section `.gnu.linkonce.t._ZNK5boost7archive17archive_exception4whatEv' of /home/cludwig/Cxx/gcc3.4/usr/lib//libboost_serialization-gcc-mt.a(basic_iarchive.o) (There are similar warnings from basic_text_iprimitive.o and xml_grammar.o. The compiler / Boost configuration are reported at the bottom of this post.) The linker generates an executable anyway and it _seems_ to work. However, I observe infrequent crashes of the application that I don't observe on a machine where I built Boost and the application (without any warnings) with gcc 3.4.2 / ld 2.14.90.0.5. Thus I suspect that the warning is there for a reason and points to the problem causing the crashes. Has anyone an idea what to do about this? I am not sure the problem is caused by the serialization library, but Googling araound I found that it is often exposed by boost_serialization-gcc-mt. There is already a gcc bugreport (PR #16625) w.r.t a similar problem but it seems neither specific to gcc 3.4.3 nor do I see a resolution. Thanks Christoph I built both Boost and my application with gcc 3.4.3: cludwig@cdcNT56:~/Cxx/gcc3.4/LaRed-0.1-BUILD> LC_ALL=C g++ -v Reading specs from /opt/gcc/gcc-3.4.3/lib/gcc/i686-pc-linux-gnu/3.4.3/specs Configured with: ../gcc-3.4.3/configure --prefix=/opt/gcc/gcc-3.4.3 --enable-threads=posix --enable-version-specific-runtime-libs --enable-languages=c,c++ --enable-__cxa_atexit --enable-c-mbchar --enable-libstdcxx-debug --enable-c99 --enable-libstdcxx-pch Thread model: posix gcc version 3.4.3 The linker is: cludwig@cdcNT56:~/Cxx/gcc3.4/LaRed-0.1-BUILD> ld -v GNU ld version 2.15.91.0.2 20040727 (SuSE Linux) Boost was built using the following script: cludwig@cdcNT56:~/Cxx/gcc3.4/LaRed-0.1-BUILD> cat ~/Cxx/boost_1_32_0/build-boost_gcc34.sh #!/bin/bash bjam -d2 --with-pydebug \ --prefix=$HOME/Cxx/gcc3.4/usr \ --builddir=$HOME/Cxx/gcc3.4/boost-1.32.0-build \ -sTOOLS=gcc \ -sBUILD="debug release <threading>multi" \ install bjam -d2 --without-python \ --prefix=$HOME/Cxx/gcc3.4/usr \ --builddir=$HOME/Cxx/gcc3.4/boost-1.32.0-build \ -sTOOLS=gcc \ -sBUILD="debug release <define>BOOST_DISABLE_THREADS <threading>single" \ install -- http://www.informatik.tu-darmstadt.de/TI/Mitarbeiter/cludwig.html LiDIA: http://www.informatik.tu-darmstadt.de/TI/LiDIA/Welcome.html