in reply to PERL5LIB not in @INC

Smartest solution would be to just treat your code like actual code and put it in a new dist.

Even smarter, put it in a repository and avoid losing it with the simplistic copy and paste setup you have now. Github is free. Even for private repos.

Install your code with cpanm and this will be one less thing you'll have to be confused about.

The smartest solution.