I'm getting a Can't use an undefined value as a HASH reference error trying to call HTTP::Message::decodable() using Perl 5.10 / libwww installed on Debian Lenny OS using the aptitude package manager. I'm really stuck so would appreciate some help please.

Here's the error:

 Can't use an undefined value as a HASH reference at (eval 2) line 1.
at test.pl line 4
main::__ANON__('Can\'t use an undefined value as a HASH reference at 
enter code here`(eval 2)...') called at (eval 2) line 1
HTTP::Message::__ANON__() called at test.pl line 6

Here's the code:

use strict;
use HTTP::Request::Common;
use Carp;
$SIG{ __DIE__ } = sub { Carp::confess( @_ ) };

print HTTP::Message::decodable();