use strict;
my $href;
fill_hashref ($href);
print qq|TEST 1: $_\t$href->{$_}| for keys %$href; # Prints NOTHING

my $empty_hash_href={};
fill_hashref ($empty_hash_href);
print qq|TEST 2: $_\t$empty_hash_href->{$_}\n| for keys %$empty_hash_href; # Works as expected

sub fill_hashref{
   my ($lref) = @_;
   $lref->{RETURNVALUE}="I would like to see this";
}