$CDs = '/usr/local/opt/podcasts/CDs';
sub dir_addup {
    my $st = stat($File::Find::name);
    $dir_total += $st->size;
}
find(\&dir_addup, $CDs);
some stuff, including creating subdir and adding files therein
find(\&dir_addup, $CDs);
Use of uninitialized value $cwd_untainted in chdir at /usr/share/perl5/File/Find.pm line 282.
Use of uninitialized value $cwd in concatenation (.) or string at /usr/share/perl5/File/Find.pm line 283.
Can't cd to : No such file or directory