Releasing a fix for this. Should be:

```scss
    .item__meta {
        @include box-sizing(border-box);

        @include rem((
            left: $gs-gutter/2,
            right: $gs-gutter/2,
            padding-bottom: $gs-baseline / 2,
            margin-bottom: -$gs-baseline / 2
        ));
    }
```