In a system distribution such as debian, it may be advisable for perl programs to ignore the user's cpan-installed modules and only use the distribution-provided modules to avoid possible breakage with newer and unpackaged versions of modules.

to that end, this pragma will replace your @inc with only the core and vendor @inc paths, ignoring site_perl and $env{perl5lib} entirely.

it is recommended that you put 'use vendorlib;' as the first statement in your program, before even 'use strict;' and 'use warnings;'.