Astro 1.6.3 broke scss imports

[Razunter]

What version of astro are you using?

1.6.10

Are you using an SSR adapter? If so, which one?

none

What package manager are you using?

pnpm

What operating system are you using?

windows

Describe the Bug

In Astro 1.6.2 I can use SCSS imports like this in .astro files:

<style lang="scss">
  @import "bootstrap/scss/functions";
  @import "bootstrap/scss/variables";
</style>

In Astro 1.6.3-1.6.10 I'm getting

Error: Undefined mixin.
    441 │ @include _assert-ascending($grid-breakpoints, "$grid-breakpoints");
      node_modules\.pnpm\bootstrap@5.2.2_@popperjs+core@2.11.6\node_modules\bootstrap\scss\_variables.scss 441:1

Also, the same thing from another angle.
In astro 1.6.2 config, this works fine:

    css: {
      preprocessorOptions: {
        scss: {
          additionalData: '@import "@css/variables.scss";',
        },
      },
    },

Astro 1.6.3 throws Error: This file is already being loaded.

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-29kwpe-br2j1m?file=src/pages/index.astro

Participation

• I am willing to submit a pull request for this issue.

[matthewp]

Most likely because of this, 1cc0670

@bluwy assigning to you, I scanned the code and didn't see anything obvious however.

[JerryWu1234]

https://stackoverflow.com/questions/29591196/sass-compiler-throws-undefined-mixin-error-when-mixins-are-kept-in-seperate-fo

I think this wasn't a bug.

you can change <style lang="scss"> @import "bootstrap/scss/functions"; @import "bootstrap/scss/variables"; </style> to
<style lang="scss"> @use "bootstrap/scss/functions" as *; @use "bootstrap/scss/variables" as *; </style>
and then to try it

[bluwy]

1.6.2 and below also seems to cause the error, which is strange because I remember seeing it work too but now it doesn't.

Anyways I traced this back to Vite's custom importer which is using an older importer API syntax (node-sass) but it should still work.

Still playing with things at the moment but I should be able to find a backwards-compatible fix.

[bluwy]

Should be fixed at vitejs/vite#11079. I'd also need to make a small change in Astro to be lenient when inling styles as some SCSS files are partials and can't be inlined.