Hi, I have an XCode c++ project that uses the static serialisation library (as well as FileSystem, IOStream and System). The project started out on XCode 3.6 on Mac OSX 10.6, where it successfully built and ran using Boost 1_49_0, built against Apple's 10.6 SDK. However, I needed to use the XCode debugger to track down some run-time issues and found I couldn't access the debugger on this version of XCode (I'm blind and have to use the VoiceOver utility to gain access to my Mac). Having taken advice, I upgraded to Mac OSX 10.8, SDK 10.8 and XCode 4.6, which solves my debugging issue. Unfortunately, my project no longer links correctly. The linker complains that it can't find symbols for my architecture (x86_64) - the messages are in the the form: "boost::archive::basic_xml_iarchiveboost::archive::xml_wiarchive::load_sta rt(char const*)", referenced from: "boost::archive::basic_xml_iarchiveboost::archive::xml_wiarchive::load_ove rride(boost::archive::version_type&, int)", referenced from: "boost::archive::basic_xml_iarchiveboost::archive::xml_wiarchive::load_ove rride(boost::archive::class_id_type&, int)", referenced from: (I've truncated the output here for brevity). I get no linker errors for any of the other Boost binaries - it's only the serialisation library that creates a problem. The project is configured to compile with the llvmgcc42 compiler, as it also uses the wxWidgets libraries, which don't support compilation using clang. Boost versions tried: 1_50_0, 1_52_0 and 1_53_0. Boost build options tried: 1 - Default (no options specified) - this worked on Mac OSX 10.6, Snow Leopard. 2 - As follows: macosx-version=10.3 macosx-version-min=10.6 architecture=combined threading=multi link=static address-model=32_64 3 - As follows: architecture=combined address-model=32_64 I'm a novice using Boost and the Mac, so would appreciate any suggestions as to how I can resolve this issue. Best wishes. Tim Burgess Raised Bar Ltd. Tel: +44 (0)1827 719822 Web: http://www.raisedbar.net We can supply Roland and Avid products with specialist pre and post-sales support for visually-impaired users - just drop us a line for a quote. Don't forget to sign our on-line petition to lobby for improved access to music education and music technology at: http://www.raisedbar.net/petition.htm