Eval::LineNumbers adds a #line "this-file" 392 comment to hereis text that is
going to be eval'd so that error messages will point back to the right place.

Please note: when you embed \n in your code, it gets expanded in double-quote
hereis documents so it will mess up your line numbering. Use \\n instead when
you can.

WWW: http://search.cpan.org/dist/Eval-LineNumbers/