<===> input.scss
$foo: 42;

.foo {
  content: $foo;
}

$condition: 1337;
@while $condition > 0 {
  $foo: $condition !global;
  $condition: 0;
}

.bar {
  content: $foo;
}

<===> output.css
.foo {
  content: 42;
}

.bar {
  content: 1337;
}