Let's verbosify it:

• select( (select(STDERR), $|++)[0] );
  [download]

• my @list = (select(STDERR), $|++);
  select(@list[0]);
  [download]

• my ($fh, $junk) = (select(STDERR), $|++);
  select($fh);
  [download]

• my $fh = select(STDERR);
  my $junk = $|++;
  select($fh);
  [download]

• my $fh = select(STDERR);
  $|++;
  select($fh);
  [download]

Makeshifts last the longest.