How can this be fixed? And shouldn't there be a big warning that trying to upgrade libc6 can break dpkg, on the Debian website page for libc6?
Best regards,
Chris Austin.
What should really be the "big warning" is mixing releases... I don't see this as possible however. How is dpkg to know that the libc6 upgrade is not for security patches or point release? I suppose something could be put in place so that the security repo is treated differently.
The best way to avoid this: Don't mix releases. When necessary, its generally safer to build the source packages. You will also realize how far you are digging into testing when you start needing to backport libs.
This is potentially reversible, but you should know in the future that core packages such as libc6, perl, python, and etc should never be mixed between releases.
I have no advice for fixing the current issue... Only avoiding it in the future.