While we are postponing the switch to 5.20, here's a preview of Per 5.22:
http://perltricks.com/article/165/2015/4/10/A-preview-of-Perl-5-22
http://www.dagolden.com/index.php/2140/paying-respect-to-modulebuild/
(It hasn't been released yet. But I expect a release within a month or so.)
Mojca