[6.2] Small breakpoint not availabe

[cietho]

When I set the following breakpoints:

$breakpoints: (
  small: 0,
  medium: 640px,
  large: 1024px,
  xlarge: 1200px,
  xxlarge: 1440px,
);
$breakpoint-classes: (small medium large);

I get this error:

Invalid null operation: "null plus "2"". on line 233:13 of D:/Documents/foundation/Scss/util/_breakpoint.scss
D:\Documents\foundation\Scss\app.scss

If I remove the small breakpoint from my $breakpoint-classes, the app.scss gets successfully compiled but there are no classes like hide-for-small or small-12.

Edit: Maybe a problem because of hard coded breakpoints? #8257

[gakimball]

I believe so—I'm going to close this in favor of #8257, where we're working towards a solution.