CSS file returning HTTP 500 (internal server error) when pushed to BigCommerce store

[jbruni]

Expected behavior

It should just load the theme's CSS file, as usual.

Actual behavior

BigCommerce server returns an internal server error (HTTP code 500).

Steps to reproduce behavior

Super simple: just add the following style in a theme's SCSS file, and push the theme to a BigCommerce store.

.anything {
    gap: min(13%, 57px);
}

This snippet of CSS passes all SCSS linting, and actually works in browsers. It should not break the entire theme's CSS. Or, at least, a hint about the issue should be provided. It has been like finding a needle in the haystack to find out this was the exact CSS rule breaking the server, since it works fine in local development with stencil start.

Thank you!