use strict;
use warnings;
use feature 'say';
use Devel::Peek;
use Storable qw/ freeze thaw /;

my $s = 'abc';
my $r = \substr $s, 1, 1;

say ref $r;                 # LVALUE
Dump $r;                    #
say ${ thaw freeze $r };    # failure

$$r = 'Z';

say ref $r;                 # LVALUE again
Dump $r;                    # ref target is now POK, PV is "Z"
say ${ thaw freeze $r };    # "Z"