PERL_UNICODE environment variable

As I understand it, the -CSD commandline option should add UTF8 to the
PerlIO layers for all file streams.  But it seems only to be applying it to
STDIN and STDOUT, and not other streams.

Anyone know what's going on?

  my $file = new IO::File($filename) or die "Error opening delimited file
$filename";
  my @layers = PerlIO::get_layers($file);
  my @layers2 = PerlIO::get_layers(\*STDOUT);
  print "Layers: ".Dumper(\@layers,\@layers2);

>perl -CSD test.pl

Output:

Layers: $VAR1 = [
          'unix',
          'crlf'
        ];
$VAR2 = [
          'unix',
          'crlf',
          'utf8'
        ];