#!/usr/bin/perl
use strict;
use warnings;

package foo;

sub fake_ARGV { print "in foo::ARGV\n" }
no warnings "once";
*foo::ARGV = *foo::fake_ARGV;

package main;

foo->ARGV;
print $ARGV[0];

##</code><code>##

~/sandbox$ perl test.pl 'Still here'
in foo::ARGV
Still here