Error when include box-shadow

[paulocoutinhox]

Hi,

Im getting this error on this line:
https://github.com/thomaspark/bootswatch/blob/v5/dist/cosmo/_bootswatch.scss#L47

Error:

Error: no mixin named box-shadow
        on line 35:12 of static/vendor/bootswatch/cosmo/_bootswatch.scss
        from line 78:9 of static/css/main.scss
>>   @include box-shadow(none);

When i comment that line it works.

Can anyone help me?

Thanks.