This isn't strictly gnulib related, but this list is the best community I know that would be able to answer this question, so pardon this slightly off-topic discussion...
I maintain some packages that contain shared libraries, for example libidn and libgsasl, and in recent releases I've added support for linker version scripts using Wl,--version-script. People have noticed that this breaks old applications linked against older libraries without symbol versions, because those applications cannot find the old symbols. That observation is correct, and it suggests that I should have incremented the shared library version of my libraries when I added symbol versioning. But that is very unfortunate, since the whole point of adding symbol versioning was to avoid versioning issues. Can anyone think of a solution out my problem? I see two painful solutions: 1) Increment the shared library version and ask people to rebuild their applications against the new shared library. The API would be identical, but the ABI has changed to used versioned symbols. 2) Drop the linker version script, declaring switching to it a failure, and reverting back to the stable API/ABI with unversioned symbols. This will break applications that were linked against the shared libraries with symbol versioning, so arguable I should increment the shared library version when I do this... What I'd like to do is: 3) Make my library export BOTH versioned and unversioned symbols, so that old applications built against an unversioned library will continue to work, and that new applications will work. Compatibility with the old symbols needs to be kept around forever, but it seems I could get the advantages of symbol versioning. I feel I'm not seeing the great benefit of symbol versioning when it is creating issues like this in practice, so it is likely that I'm missing some fundamental insight. I have read Drepper's DSO-Howto, but it is more targeted towards people who like to know how things work, rather than as a guide for maintainers, and I'm having trouble translating the theory into a best practice. It's also rather focused on ELF/glibc systems. Thanks for any guidance, /Simon
