Long before this distro showers, I always knew that the "standard" Perl module directory started with /usr/lib/perl5. Whenever I installed Perl myself, I never felt the need to reconfigure @INC or other stuff, except once or twice for debugging and thread options. Why? Because I always intented to replace Perl (including non-core modeuls, if any) came with the distro. Before I leave this old history, just in case it rang a bell, I just want to emphasize that "I always wonder why Linux distros...." is not a real question. I can understand the reason behind distros decision, I just don't like the result.

You don't really ever know where the "standard" Perl module directory is, do you?

If you really asked me refering to the Perl installation shipped with a random distro, my answer was: I would never be sure until I did some test or lookup.

So, put the long story short, eventually, only this application in this particular distribution that sets @INC in such way. I believe this @INC hackery (borrowed from Tanktalus) won't affect other systems I don't need or don't have any interest to control.

I know it's against common practices, it's against my standard practices as well. I think the hard part with my OP is that it tries to force a frame, unusual frame of thinking. Now I can see it fails :-) That's why I said earlier that "Let's put aside for a while the debate around....". I kinda expected typical reactions I got so far, which I'm grateful for because it lets me know my sanity level (or, is it my insanity level?)

If you can make your system ten times as reliable by breaking convention, then do it and document the decision process

I will, and thanks for reminding me. My OP is absolutely part of the docs :) The lengty was mostly to accommodate my intention to share what I went through during the process of the decision making. The part I apologized because I realized it might end up useless to anybody else.