Выпилил src/scss/functions.scss

config.js

@@ -13,7 +13,6 @@ let config =
     "object-fit-polyfill",
   ],
   "addStyleBefore": [
-    "src/scss/functions.scss",
     "src/scss/variables.scss",
     "src/scss/mixins.scss"
   ],

src/blocks/blocks-library/blocks-library.scss

-@import "../../scss/functions.scss";
 @import "../../scss/variables.scss";
 @import "../../scss/mixins.scss";
 @import "../alert/alert.scss";

src/scss/functions.scss

-$font-size--root:             16px !default;
-
-@function rem($px, $font-size: $font-size--root) {
-  @return ((($px / ($px * 0 + 1)) * 100 / ($font-size / 1px)) / 100) * 1rem;
-}