I have two answers for that, please pick the one that seems more
appropriate to you. But please consider both.
(1) I actually was intending to say Config::Tiny. It's not declared as
prerequisite and is used in lib/PITA/XML/Request.pm, line 46. I have
actually seen fails due to missing Config::Tiny
(2) I find YAML::Tiny in inc/Module/Install/Metadata.pm, line 292
I don't know if the code can be reached.