-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 It appears that on some platforms, the boost build system is not aware of the necessary compiler flags that must be set when using shared libraries. In my experience, under gcc 4.0 if one doesn't effectively make *all* symbols visible via -fvisibility=default, for both the dynamic libraries and the executable that uses them, then compiler generated RTTI information will *not* be shared. I believe that - -fvisibility=default for dynamic libraries is the default setting but when an executable is being built it seems that -fvisibility=hidden is the default. <complaint> The fact that in order to safely use C++ with dynamic libraries on this platform one must effectively make all symbols visible is an unpleasant state of affairs with a number of ramifications. But this is a topic for another list. </complaint> We are fortunate that in one of the boost::signals test executables, this leads to a repeatable crash (boost_any_bridge fails to detect that two types are the same (because of an erroneous type info comparison). It is much worse in some other situations. I have seen silent failures (such as the "type" of a standard exception being changed between where it is thrown and where it is caught). I have tested this crash and fix (by manually recompiling the executable with all symbols visible) on the darwin gcc 4.0 platform using boost build v2. I just noticed the boost bug report #1262038 <http://sourceforge.net/tracker/?func=detail&atid=107586&aid=1262038&group_id=7586> with the exact same stack crawl, so I believe it is a more general phenomenon. Can anyone suggest patches to the build system to support the safe use of shared libs with gcc 4.0? Thanks, Mat -----BEGIN PGP SIGNATURE----- Version: PGP Desktop 9.0.2 (Build 2424) iQA/AwUBQwTRixIZBaoznf65EQI3aACfXHYAI5bLL1buAaNqpjsQcGkgJI8AoLQx O5LGuDL1ujZdPIx5AvOvdO3B =HhtX -----END PGP SIGNATURE-----