[Boost-users] [Serialization] issue with "Assertion `__null != bpos' failed"

Subject: [Boost-users] [Serialization] issue with "Assertion `__null != bpos' failed"
From: Francois Mauger (mauger_at_[hidden])
Date: 2017-04-24 21:22:34

Hi Robert, all,

In some of our libs, we use serialization through a base pointer:

We have a base (abstract) class "a::base" which is available from a 
shared library "liba".
We have created a new class "b::foo", inherited from "a::base", hosted 
in another shared lib "libb", "libb" being explicitly linked to "liba". 
In "libb", class "b::foo" is exported through :

BOOST_CLASS_EXPORT_KEY2(b::foo,"b::foo") (in header foo.hpp)
BOOST_CLASS_EXPORT_IMPLEMENT(b::foo) (in some libb's foo-serial.cpp 
source file)

which I think is the right way to process to register a class in a 
compilation unit.

In a test program, I (de)serialize 'b::foo' instances through a 
'a::base' pointer.
This mechanism has worked for years in all of our software chains.
And today it works with our current production software system (ubuntu 
linux 16.04, g++ 5.4.0, GNU ld 2.26.1, Boost 1.60).
However, we now face a runtime error on *some* of our boxes. The message is:

<pre>
...test_app...: 
/path/to/boost/install/include/boost/archive/detail/oserializer.hpp:436:
static void 
boost::archive::detail::save_pointer_type<Archive>::polymorphic::save(Archive&, 
T&) [
with T = a::base; Archive = boost::archive::xml_oarchive]: Assertion 
`__null != bpos' failed.
Abort (core dumped)
</pre>

This error only occurs with XML or txt archives, but works like a charm 
with Christian's EOS portable binary ars.
What is strange is that the code works on some of our systems but failed 
on other ones with the
same compiler/linker/boost versions. The exception suggests some problem 
with class registration
but I don't understand this (apparently) arbitrary behaviour.

If any of you have a hint to help us to find the solution, it would be 
appreciated.
thanks

regards
-- 
François