Using a clean build and default install of 1.36 release branch checked out today (r47978) on OSX 10.5.4 using gcc 4.0.1, I get the following linker error : Ld /Users/matthiasschabel/Projects/CGFFT/build/Release/CGFFT normal i386 cd /Users/matthiasschabel/Projects/CGFFT /Developer/usr/bin/g++-4.0 -arch i386 -isysroot /Developer/SDKs/ MacOSX10.5.sdk -L/Users/matthiasschabel/Projects/CGFFT/build/Release - L/Applications/MATLAB74/bin/maci -F/Users/matthiasschabel/Projects/ CGFFT/build/Release -filelist /Users/matthiasschabel/Projects/CGFFT/ build/CGFFT.build/Release/CGFFT.build/Objects-normal/i386/ CGFFT.LinkFileList -mmacosx-version-min=10.5 -lfftw3_threads -lgsl - lgslcblas -lfftw3 -lmpi -lboost_mpi-xgcc40-mt -lboost_serialization- xgcc40-mt -lboost_system-xgcc40-mt -lmpi_cxx -leng -lmx -lboost_thread- xgcc40-mt -o /Users/matthiasschabel/Projects/CGFFT/build/Release/CGFFT Undefined symbols: "boost ::serialization ::detail ::extended_type_info_typeid_0 ::less_than(boost::serialization::extended_type_info const&) const", referenced from: vtable for boost ::serialization ::detail::extended_type_info_typeid_1<std::complex<double> const>in test_cgfft.o vtable for boost ::serialization::detail::extended_type_info_typeid_1<std::pair<double, std::complex<double> > const>in test_cgfft.o "boost::mpi::detail::mpi_datatype_cache", referenced from: __ZN5boost3mpi6detail18mpi_datatype_cacheE$non_lazy_ptr in test_cgfft.o "boost::serialization::extended_type_info::self_register()", referenced from: boost ::serialization::detail::extended_type_info_typeid_1<std::pair<double, std::complex<double> > const>::extended_type_info_typeid_1()in test_cgfft.o boost ::serialization ::detail::extended_type_info_typeid_1<std::complex<double> const>::extended_type_info_typeid_1()in test_cgfft.o ld: symbol(s) not found collect2: ld returned 1 exit status Any ideas on what's happening here? Matthias