Of course alternative solution, as Emil suggests, is not to change boost::serialization, but to register the classes manually (with manually chosen identifier string). But then we at least need a BIG FAT warning in the documentation regarding the use of BOOST_CLASS_EXPORT, and a possible pitfall: code refactoring loses archive compatibility.
There is another warning which is missing from the documentation: portable code can not rely on BOOST_CLASS_EXPORT to register a class unless the user explicitly calls a function from a compilation unit that "sees" that particular BOOST_CLASS_EXPORT call. This is because it relies on a global object's constructor to initiate the registration process, but a good compiler will deadstrip all such global objects unless the user explicitly calls a function from the compilation unit that defines them. In other words BOOST_CLASS_EXPORT isn't automatic because a portable program is required to (manually) call a (possibly empty) function from the registered class' cpp file. This is contradictory to BOOST_CLASS_EXPORT's intended use to register derived classes automatically, just by linking their cpp files. Emil Dotchevski