package example;
use v5.10;
   use warnings;
   use strict 'subs';
   use feature 'state';

require Exporter;

our ($VERSION, @ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS);
@ISA = qw(Exporter);
$::debug=1;
{
our $debug;
   say "debug=$debug";
}
$VERSION = '1.10';
1;

and the test script:

<code>
#!/usr/bin/perl
#:: test of ours

   use v5.10;
   use warnings;
   use strict 'subs';
   use feature 'state';
   use lib '.';
   use example;

   say "debug=$debug";

##</code><code>##


[255]  # perl test_our_behaviour.pl
<code>
[0]  # perl test_our_behaviour.pl
Use of uninitialized value $example::debug in concatenation (.) or string at example.pm line 14.
IN EXAMPLE: debug=
debug=1