#!/usr/bin/env perl
use 5.010_000;
use strict;
use warnings;

{   package MyTest;
    my  $global  = 'global variable';
    our $package = 'package variable';
    sub access_global { return $global }
    1;
}

{   package main;
    my $package_var = $MyTest::package;
    my $global_var  = MyTest::access_global();
    my $warning_var = eval { $MyTest::global };
    say ">$_<" for $package_var, $global_var, $warning_var;
}

__END__
>package variable<
>global variable<
><
Name "MyTest::global" used only once: possible typo at /Users/io1/Workspace/example/package_variables.pl line 16.
Use of uninitialized value $_ in concatenation (.) or string at /Users/io1/Workspace/example/package_variables.pl line 18.