$old ne $new or exit 0;
my $subj = '[' . $subject_prefix . ($ref eq 'master' ? '' : "/$ref") . ']';
-my $tmpdir = File::Temp->newdir() or die;
-my $outname = "$tmpdir/0";
-my $out = IO::File->new($outname, '>') or die;
+my $out = File::Temp->new() or die;
+my $outname = $out->filename;
$out->autoflush(1);
close STDOUT;
open STDOUT, '>&', $out or die;