SassC::SyntaxError: Error: style declaration must contain a value

[mayur-kambariya]

During deploy rails application on heroku

[mdo]

This looks like any error on your part? Can't see anything that says Bootstrap is to blame here.

[r1x1]

@mdo We're also seeing this, it appears that it was introduced in v4.5.1 with this change: #30957

You'll also see another comment on that issue reporting the same problem.

For now we're pinning at v4.5.0 to avoid this.

[ffoodd]

Nullifying the value should not output the property. What's the Sass compiler you use?

[r1x1]

Nullifying the value should not output the property. What's the Sass compiler you use?

In our case Bootstrap (bootstrap/scss/bootstrap.scss) is being passed through the newest release of the sassc-ruby gem, which it appears is using LibSass 3.6.1 for compilation.

For completeness, the error we're seeing:

SassC::SyntaxError: Error: style declaration must contain a value
        on line 8038:13 of stdin
>>   box-shadow:;

   ------------^

[XhmikosR]

Have you tried reporting the issue upstream?

We only test node-sass and dart sass and we cannot guarantee things will work with other implementations.

[leoplct]

We are having the same issue +1

[XhmikosR]

#32019 (comment)

[XhmikosR]

@ffoodd @MartijnCuppens @mdo: since people don't seem to report the issue upstream

1. we either report it upstream ourselves and hope they fix it
2. figure out if we can revert the offending change
3. ignore the issue since it's something we don't test nor use ourselves

[ffoodd]

From my understanding:

1. @rasbary mentionned that the sassc-ruby gem used Libsass under the hood, and Libsass is deprecated. So either we report
   • upstream #1 (sassc-ruby gem) and suggest to switch to dart-sass
   • upstream #2: Libsass compilation failure when nullifying a value (if it can be reproduced with Libsass directly)
2. @rasbary also spotted the offending PR (nullify custom forms states' box-shadow #30957) which can be reverted easily, with as single drawback to output a few useless box-shadow: none.

FYI: I tried things out on Sassmeister and whatever compiler I use, nothing wrong happens.

[MartijnCuppens]

Yeah, pretty weird it happens now, since we we've been using null variables for quite a while now (#28035)

[mdo]

I think this is something we ignore and close as a won't fix? Seems like there's not much to change here and we're on Dart Sass now.

[XhmikosR]

We also have #29760 FYI.

[mdo]

Yeah, I say we close for that issue.

[yoones]

I have the same issue when I put $enable-shadows: true; in my scss file. Setting this to false doesn't trigger an error.

yarn package.json: "bootstrap": "^4.5.3"

[Frimlik]

I have the same issue when I put $enable-shadows: true; in my scss file. Setting this to false doesn't trigger an error.

yarn package.json: "bootstrap": "^4.5.3"

I think $enable-shadows: true; is the default value. At least I haven't found this command in my code.
I spent few days and sleepless nights implanting node-sass-json-importer into Angular 10 (to be able to use values from json file in scss) and this was my last obstacle...
But interesting thing for me was that when I looked at #30957 and did "revert" in my local code (insert none instead of null), everything worked fine as well.

[wongwf82]

This answer on SO worked for me:
https://stackoverflow.com/questions/70401077/rails-7-asset-pipeline-sasscsyntaxerror-with-tailwind/70665740#70665740

I put inside production.rb and deployment to Heroku was fine, while retaining gem "sassc-rails" in my Gemfile though.