Description of problem: The Fedora 17 base comes with perl-threads-1.86-2.fc17. Fedora 17 updates contains perl-threads-1.83-219.fc17. The changelogs for these two package versions look entirely different.
Core perl modules in Fedora now come from one of two sources: 1. as a subpackage of the main perl module, which will generally be the version bundled with the upstream perl distribution 2. as a separately maintained (standalone) package based on an upstream release from CPAN In this case, the Fedora perl package includes version 1.83 of perl-threads and the standalone package is version 1.86. The point of splitting out these packages into their own packages is so that they can be updated more easily without having to respin the whole perl package for every module update, requiring 100 MB or so download of unchanged perl code for a few KB of module update. So when an updated perl version is issued to fix an actual perl bug, it may contain some perl module subpackages that are older than the ones already issued. This doesn't matter - the standalone package is the one that's being kept up to date and the one that ends up on users' systems. That's what's intended. Now it might be argued that the main perl package shouldn't generate subpackages for modules that are maintained separately in Fedora. I can see the logic in that argument. But it wouldn't make any difference to the end users - they get the latest (highest numbered, rather than chronologically built) version whether it comes from the main perl package or the standalone package, and that's what's intended. And that's also why the changelogs for the two packages are different - they are built from different source packages.
Okay, sounds like NOTABUG to me. In case anyone else discovers this, I also see older versions of perl-Carp perl-Scalar-List-Utils perl-threads-shared in the F17 updates repository, but I'm only checking packages that are installed on my system.
Indeed. There are a lot of sub-packaged modules for the perl package that will exhibit similar behaviour.