<===> input.scss
$x: -42;
$y: -84;
div {
  $x: 42;
  $y: 84;
  for {
    @for $x from 1 through 5 {
      $y: $y + 5;
      y: $y;
      x: $x;
      $x: 999;
      x: $x;
      $y: -9 !global;
      $x: -9 !global;
    }
  }
  x: $x;
  y: $y;
}
<===> output.css
div {
  x: 42;
  y: 109;
}
div for {
  y: 89;
  x: 1;
  x: 999;
  y: 94;
  x: 2;
  x: 999;
  y: 99;
  x: 3;
  x: 999;
  y: 104;
  x: 4;
  x: 999;
  y: 109;
  x: 5;
  x: 999;
}