my $command_sub;
{
  my $x_at_time_of_sub_definition = $user_x->get();
  my $y_at_time_of_sub_definition = $original_y;
  $command_sub = sub {
    print_entries(
      $x_at_time_of_sub_definition,
      $y_at_time_of_sub_definition,
    );
  }
}
$mw->Button (
  -command => $command_sub,
);