Extension scss isn't being discovered

[dgkf]

Bug description

Following up on the bug fix from #3414, the patched version of the code seems to not discover/use extension scss at all.

Given just a _variables.scss file that includes a single line,

@import "definitely/not/a/file"

Quarto will render the document without issue, even though this file clearly should throw an error.

Possibly related - In the process of testing this out, I also couldn't seem to clear quarto's cache entirely. A previous iteration of this test used $primary: #F00; as the contents of the _variables.scss file and this is still affecting the webpage's style, even in a private browser or separate browser entirely. I've tried deleting every quarto-generated file I can find and running with --no-cache, but can't seem to get rid of this cached stylesheet. Perhaps this is related to the current file not throwing errors. Is there a better way to get quarto to render a project from scratch?

Steps to reproduce

1. Clone this repo: https://github.com/dgkf/quarto-revealjs-theme-reprex (@quarto-cli-issue-5794)
2. Run quarto preview
3. Quarto should successfully build the webpage
4. Open _extensions/custom/scss/_variables.scss and observe that it should throw a SCSS file-not-found error

Expected behavior

_variables.scss from the extension is picked up by quarto, resulting in an error

Actual behavior

Site builds, and does not appear to use the theme scss

Your environment

• MacOS
• quarto-cli b5c6ddc37cb2c34e7d6da01cff13b640e97c22cc (June 2, 2023)

Quarto check output

[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.1.2: OK
      Dart Sass version 1.55.0: OK
      Deno version 1.33.2: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 99.9.9
      Path: /Users/kelkhofd/Projects/quarto-cli/package/dist/bin

[✓] Checking basic markdown render....OK

[✓] Checking Python 3 installation....OK
      Version: 3.11.3
      Path: /opt/homebrew/opt/python@3.11/bin/python3.11
      Jupyter: 5.3.0
      Kernels: julia-1.8

      NOTE: No Jupyter k

Note, I omitted errors finding R because I run R in a docker container and quarto doesn't like that it can't find it's system temp session directory. I'm pretty sure it's unrelated to this bug.

[dragonstyle]

Thanks for reporting this, I've have a look at why we're not throwing.

As far as the cache not properly invalidating, this is definitely caused because the key for cache validation is a hash of the scss theme file contents (not its imports, incorrectly). Since the changes are limited to the imported files, we are missing those changes and using the cache. I'll definitely do something about this to make it automatic.

[dragonstyle]

Thx again, a fix is on the way!