Compiling foundation-sites with a current version of SASS (1.43.4), throws various of those issues:

Warning: You probably don't mean to use the color value white in interpolation here.
It may end up represented as white, which will likely produce invalid CSS.
Always quote color names when using them as strings or map keys (for example, "white").
If you really want to use the color value here, use '"" + $name'.

╷

377 │ &.#{$name} {
│ ^^^^^
╵
node_modules/foundation-sites/scss/components/_button.scss 377:15 foundation-button()

Needs to be fixed by writing the selector like so:

&#{"." + $name} {

or

&.#{"" + $name} {

.. but the first one doesn't look that ..hacky.