Fatal error with sass@1.32.x when Deprecation Warning is raised.

[jsg2021]

• Operating System: linux
• Node Version: 14.15.3
• NPM Version: 7.4.0
• webpack Version: 4.46.0
• sass-loader Version: 10.1.1

Expected Behavior

Raise the warning in webpack without crashing.

Actual Behavior

Webpack crashes.

How Do We Reproduce?

in a sass file, use a color value of hsla(0,0,0, 0.025).
if you run the sass cli on it:

sass ./node_modules/foundation-sites/scss/foundation.scss ./tmp.css
Deprecation Warning: $saturation: Passing a number without unit % (0) is deprecated.

To preserve current behavior: $saturation * 1%

   ╷
25 │ $side-nav-link-bg-hover: hsla(0, 0, 0%, 0.025) !default;
   │                          ^^^^^^^^^^^^^^^^^^^^^
   ╵

webpack prints this and a long stack trace and dies:

ModuleBuildError: Module build failed (from ../node_modules/sass-loader/dist/cjs.js):
SassError: NoSuchMethodError: method not found: 'get$span' on null
   ╷
25 │ $side-nav-link-bg-hover: hsla(0, 0, 0%, 0.025) !default;
   │                          ^^^^^^^^^^^^^^^^^^^^^
   ╵

[alexander-akait]

This deprecation error from sass, please fix problem in core, we can't fix it on our side, sorry

[jsg2021]

The deprecation warning is being miss read by sass-loader? it works as expected when used by their cli?

[alexander-akait]

hm, weird, SassError: NoSuchMethodError: method not found: 'get$span' on null means, dart-sass/node-sass throws the error, give me couple minutes to investigate

[alexander-akait]

@jsg2021 weird, can't reproduce, can you check verison of dart-sass or provide simple reproducible test repo?

[alexander-akait]

Tests - #915

[alexander-akait]

Maybe you have globally installed version is newer than in local node_modules

[jsg2021]

As I isolate parts, it stops reproducing... very strange. If I set fiber: false in my main project the warning is not even caught by the loader and is directly printed to the console and webpack does not know there was a warning. Actually, in isolation, that's what happens too... webpack is not aware there was a warning. Maybe this is a race condition and needs more files to process?

[alexander-akait]

If I set fiber: false in my main project the warning is not even caught by the loader and is directly printed to the console

sass doesn't allow to set custom loggers, so expected

Maybe this is a race condition and needs more files to process?

It means bug inside fiber

[jsg2021]

I think you are correct, in that there isn't an error in sass-loader. I think the we can catch it though... it looks like it's thrown when the SassError toStrings the original error.