Why won't this basic Parse::RecDescent example work?

[7stud]

Dear Monks,

Why the <deleted> does this code show an empty hash:

use strict; 
use warnings; 
use 5.012;

use Parse::RecDescent;

$::RD_ERRORS = 1; #Parser dies when it encounters an error
$::RD_WARN   = 1; # Enable warnings- warn on unused rules &c.
$::RD_HINT   = 1; # Give out hints to help fix problems.

my %HASH;

my $grammar = <<'END_OF_GRAMMAR';

    startrule : dir
             { $main::HASH{dir} = $item{dir} }

    dir : 'hello'

END_OF_GRAMMAR

my $parser = Parse::RecDescent->new($grammar);
$parser->startrule("hello"); 

use Data::Dumper;
say Dumper(\%HASH);

--output:--
$VAR1 = {};