What CountZero said plus make sure your Moose and Class::MOP stuff jibe (there have also been issues with Mech and LWP regarding non-meaningful testing failures). I love Moose but it has been a sore spot in keeping things stable for quite awhile.

If all the requirements are in you should definitely be able to use any given Cat app in various spaces. Also make sure your PERL5LIB, etc, isn't causing problems. If it's still not working, maybe come back with some examples of the errors / problems?