Comment 10 for bug 1000508

this is a change in GCC 4.7's c++11 mode (see http://gcc.gnu.org/wiki/Cxx11AbiCompatibility). There is no "easy" solution. c++0x/c++11 mode is still marked experimental in GCC, so better don't use it in production code. so either:

 - build qapt in c++98 mode
 - rebuilding libapt-pkg in c++11 mode isn't a solution, because it will break binaries,
    which are built in c++98 mode.
 - build libapt-pkg both in c++98 and c++11 mode with a different soname. This approach
   doesn't scale for the whole distribution.
 - avoid the ABI incompatibility by changing libapt-pkg's ABI, so that it works with both
   c++98 and c++11 mode ().

The last one may be an option until you find the next incompatibility, so in the long term it might be better to just build in c++98 mode.