use strict;
use Scope::Guard;

my $x;

my $code = do {
    my $g;
    sub {
        my $z;
        $g = Scope::Guard->new( sub { warn "destroyed"; $z } );
    }
};

use Scalar::Util ();
Scalar::Util::weaken(my $code2 = $code);

$code->();
printf "code2: %d\n", !!(defined $code2);
undef $code;
printf "code2: %d\n", !!(defined $code2);
warn "end";

##</code><code>##

code2: 1
code2: 1
end at x.pl line 21.
destroyed at x.pl line 10 during global destruction.