use strict;
use warnings;

use Devel::Carnivore;

my $h;
{
	my %h : Watch('%h');

	$h{fname} = "Foo";
	$h = \%h;	
}
$h->{lname} = 'Bar';

unwatch $h;

$h->{email} = 'foo@bar.com';

##</code><code>##

$perl carnivore.pl
# variable is now under observation
> %h: "fname" changed from "" to "Foo"  at carnivore.pl line 10
> %h: "lname" changed from "" to "Bar"  at carnivore.pl line 13
# mission completed