Build options stylePreprocessorOptions->sass->silenceDeprecations no longer working after upgrade to Angular 20.

[dailytabs]

Which @angular/* package(s) are the source of the bug?

Don't known / other

Is this a regression?

Yes

Description

                        "stylePreprocessorOptions": {
                            "sass": {
                                "silenceDeprecations": [
                                    "mixed-decls",
                                    "color-functions",
                                    "global-builtin",
                                    "import"
                                ]
                            }
                        },

None of that works anymore - warnings all over the place. Can't resolve any of this until bootstrap 6, so these need silenced.

Please provide a link to a minimal reproduction of the bug

No response

Please provide the exception or error you saw

Global built-in functions are deprecated and will be removed in Dart Sass 3.0.0.
Sass @import rules are deprecated and will be removed in Dart Sass 3.0.0.
etc.

Please provide the environment you discovered this bug in (run ng version)

Angular CLI: 20.0.3
Node: 22.16.0
Package Manager: npm 11.4.1
OS: linux x64

Angular: 20.0.4
... animations, common, compiler, compiler-cli, core, forms
... localize, platform-browser, platform-browser-dynamic
... platform-server, router

Package                      Version
------------------------------------------------------
@angular-devkit/architect    0.2000.3
@angular-devkit/core         20.0.3
@angular-devkit/schematics   20.0.3
@angular/build               20.0.3
@angular/cdk                 20.0.3
@angular/cli                 20.0.3
@angular/youtube-player      20.0.3
@schematics/angular          20.0.3
rxjs                         7.8.2
typescript                   5.8.3
zone.js                      0.15.0

Anything else?

Appears that the new builder ignores these options.
Nothing related appears on the Update Guide.

[alan-agius4]

I'm sorry, but we can't reproduce the problem following the instructions you provided.
Remember that we have a large number of issues to resolve, and have only a limited amount of time to reproduce your issue.
Short, explicit instructions make it much more likely we'll be able to reproduce the problem so we can fix it.

If the problem persists, please open a new issue following our submission guidelines.

A good way to make a minimal repro is to create a new app via ng new repro-app and add the minimum possible code to show the problem. Then you can push this repository to github and link it here.