Testers needed for dev-lang/perl-5.20.1-r4 (stabilization candidate)

Most of us in the Gentoo Perl packaging team are already running ~arch Perl even on otherwise stable machines, and Perl 5.20 is looking very good so far. Our current plan is to wait for another month or similar and file the stabilization request for it in February. This would be a real achievement, since we'd at that time actually have the latest and greatest upstream stable Perl release also stable in Gentoo; this hasn't been the case for a very long time.
Of course, we need testers for that; the architecture teams cannot possibly try out all Perl programs in Gentoo with the new version. So, if you're feeling adventurous, and if you are running a fully updated stable system, please help us!
What do you need to do? First, upgrade perl-cleaner to ~arch by placing the following line in your package.keywords (or package.accept_keywords)

app-admin/perl-cleaner

and updating perl-cleaner (to currently 2.19):

emerge -u1a perl-cleaner

Then, upgrade Perl (and only Perl) to ~arch by placing the following exact three lines in your package.keywords (or package.accept_keywords):

dev-lang/perl
virtual/perl-*
perl-core/*

Then, upgrade your system with

emerge -uDNav world
perl-cleaner --all

This should now already be much easier than with previous Perl versions. In theory, all Perl packages should be rebuilt by emerge via the subslot rebuild mechanism, and perl-cleaner should not find anything to do anymore, but we cannot be 100% sure of that yet so far. (Looking forward to feedback.)
Well, and then use Perl and use your system, and if you encounter any problems, file bugs!!!

A final remark, once Perl 5.20 becomes stable you may want to remove above keywording lines from your portage configuration again.