[SOLVED] Sass - TypeError: Cannot read properties of undefined (reading 'indexOf')

Sass - TypeError: Cannot read properties of undefined (reading 'indexOf')

My build on the server failed today, suddenly, when doing its Sass thing it's always done for 4 years.

It runs in Docker so the image probably has a later npm than I have locally, since I don't tend to update things that work.

So I updated my local node and npm and replicated the issue.

TypeError: Cannot read properties of undefined (reading 'indexOf')
    at /Users/me/myCode/node_modules/sass/sass.dart.js:116832:12
    at Object.applyHooksTransformer (/Users/me/myCode/node_modules/sass/sass.dart.js:1863:14)
    at Object.initHooks (/Users/me/myCode/node_modules/sass/sass.dart.js:1843:251)
    at Object.initNativeDispatchContinue (/Users/me/myCode/node_modules/sass/sass.dart.js:1809:9)
    at Object.initNativeDispatch (/Users/me/myCode/node_modules/sass/sass.dart.js:1803:9)
    at Object.getNativeInterceptor (/Users/me/myCode/node_modules/sass/sass.dart.js:29308:13)
    at Object.getInterceptor$x (/Users/me/myCode/node_modules/sass/sass.dart.js:29569:16)
    at Object.set$compile$x (/Users/me/myCode/node_modules/sass/sass.dart.js:29636:16)
    at Object.main (/Users/me/myCode/node_modules/sass/sass.dart.js:24401:9)
    at main2 (/Users/me/myCode/node_modules/sass/sass.dart.js:26210:9)

I've "gone up" through some major versions of both sass and gulp-sass but even latest doesn't work.
I've cleared the cache and reinstalled these packages.
I use Sass to build Bootstrap and a single custom.scss file.
I have not yet checked-out an old commit from Git.
It last built on Weds 18th Oct and it's now Mon 23rd.
I've been working far from any of this in C# code.
I've had only 4 hours sleep and this error showed up on a bad day for me.
AI is out of ideas.

The failure is spontaneous and unexpected.

My guess is that the Node Docker image was updated this weekend and this has broken Sass somehow.

Updates

The official Node docker image was updated..... 4 days ago.

Solution

Looks exactly like an error I just spotted yesterday. Check the version of node you are using in the docker image, if it's 21 or current just downgrade to 20.

Looks like a common issue already: https://github.com/vercel/next.js/issues/57005