Agreed! Here are two other cases, and the second one is quite interesting:

Share the reference of an array, cause the same problem:

use threads;
use threads::shared;

use Data::Dumper;

use warnings;
use strict;


my $a = [1,2];
print Dumper($a);
share($a);
print Dumper($a);
[download]

This printed:

$VAR1 = [
          1,
          2
        ];
$VAR1 = [];
[download]

More interestingly ;-) share an element of an array, does not lose the content, but alter the content:

use threads;
use threads::shared;

use Data::Dumper;

use warnings;
use strict;


my $a = [1,2];
print Dumper($a);
share($a->[0]);
print Dumper($a);
[download]

This gives you:

$VAR1 = [
          1,
          2
        ];
$VAR1 = [
          '1',#look at this
          2
        ];
[download]