use IO::Capture::Stderr;
  my $capture = IO::Capture::Stderr->new();
  $capture->start();       # start captured


  # your stuff here...

  print STDERR "...\n";    # STDERR is captured
  print "...\n";           # STDOUT is not captured



  # at the end
  $capture->stop();        # stop capture
  my @err = $capture->read;
  if ($#err >= 0) {        # any captured error?
    print "$_" for @err;   # print stderr to screen
    <STDIN>;               # wait for input
  }