At the start of your first-linked P5P thread, haukex:

Which means simply saying "welp, . isn't in @INC anymore" is going to leave a vast number of broken scripts, most of them likely the ones whose users are least knowledgable about perl (do 'config.pl' is very common baby perl, I think).

Fair comment!

I'm likely to solve it by automating a massive search-and-replace, inserting a './' before all filenames. (Might just back up first!). I think I know enough to know that the removal of '.' from @INC is best not over-ridden!

Many thanks to everyone who contributed to this. You are a wise and, yes, very attractive bunch of people!