Unable to modify $utilities map after loading Bootstrap v6-dev modules

[baderpaul]

I am a TYPO3 developer from Germany and would like to use Bootstrap 6 in the future for site packages, similar to how it is used in WordPress.
First of all, I really like the ideas behind the new version and have been experimenting with Bootstrap v6 since last year.
Environment:

Bootstrap: v6.0.0-dev (from v6-dev branch)
Sass: Dart Sass 1.95.0
Build tool: npm

I am currently testing how the utilities can best be customized and overridden individually.

My Sass file to be compiled currently looks like this:

I tested it with from your example from

https://v6-dev--twbs-bootstrap.netlify.app/docs/6.0/utilities/api/#modify-utilities

//@use "sass:map";
@use "../../Public/Contrib/bootstrap/scss/banner";

// scss-docs-start import-stack
//@use "../../Public/Contrib/bootstrap/scss/colors";
//@use "Custom/c-colors";
//@use "Custom/c-theme";

// Global CSS variables, layer definitions, and configuration
@use "../../Public/Contrib/bootstrap/scss/root";

// Subdir imports
@use "../../Public/Contrib/bootstrap/scss/content";
@use "../../Public/Contrib/bootstrap/scss/layout" ;
@use "../../Public/Contrib/bootstrap/scss/forms";
@use "../../Public/Contrib/bootstrap/scss/buttons";

// Components
@use "../../Public/Contrib/bootstrap/scss/accordion";
@use "../../Public/Contrib/bootstrap/scss/alert";
@use "../../Public/Contrib/bootstrap/scss/avatar";
@use "../../Public/Contrib/bootstrap/scss/badge";
@use "../../Public/Contrib/bootstrap/scss/breadcrumb";
@use "../../Public/Contrib/bootstrap/scss/chip";
@use "../../Public/Contrib/bootstrap/scss/card";
@use "../../Public/Contrib/bootstrap/scss/carousel";
@use "../../Public/Contrib/bootstrap/scss/datepicker";
@use "../../Public/Contrib/bootstrap/scss/dialog";
@use "../../Public/Contrib/bootstrap/scss/drawer";
@use "../../Public/Contrib/bootstrap/scss/menu";
@use "../../Public/Contrib/bootstrap/scss/list-group";
@use "../../Public/Contrib/bootstrap/scss/nav";
@use "../../Public/Contrib/bootstrap/scss/nav-overflow";
@use "../../Public/Contrib/bootstrap/scss/navbar";
@use "../../Public/Contrib/bootstrap/scss/pagination";
@use "../../Public/Contrib/bootstrap/scss/placeholder";
@use "../../Public/Contrib/bootstrap/scss/popover";
@use "../../Public/Contrib/bootstrap/scss/progress";
@use "../../Public/Contrib/bootstrap/scss/spinner";
@use "../../Public/Contrib/bootstrap/scss/stepper";
@use "../../Public/Contrib/bootstrap/scss/toasts";
@use "../../Public/Contrib/bootstrap/scss/tooltip";
@use "../../Public/Contrib/bootstrap/scss/transitions";

// Helpers
@use "../../Public/Contrib/bootstrap/scss/helpers";

// Custom

$utilities: map.merge(
  $utilities,
  (
    "border": map.merge(
      map.get($utilities, "border"),
      ( responsive: true ),
    ),
  )
);

// Utilities
@use "../../Public/Contrib/bootstrap/scss/utilities/api";
// scss-docs-end import-stack

After compilation
i get an error like that:

baderp@baderps-MBP setup_package % ddev npm run build

setup_package@1.0.0 build
sass Resources/Private/Scss/StyleSheet.scss:Resources/Public/Styles/StyleSheet.css && sass --style=compressed Resources/Private/Scss/StyleSheet.scss:Resources/Public/Styles/StyleSheet.min.css

Error: There is no module with the namespace "map".
╷
50 │ $utilities: map.merge(
│ ┌─────────────^
51 │ │ $utilities,
52 │ │ (
53 │ │ "border": map.merge(
54 │ │ map.get($utilities, "border"),
55 │ │ ( responsive: true ),
56 │ │ ),
57 │ │ )
58 │ │ );
│ └─^
╵
Resources/Private/Scss/StyleSheet.scss 50:13 root stylesheet

After compilation with
@use "sass:map";
i get an error like that:

baderp@baderps-MBP setup_package % ddev npm run build

setup_package@1.0.0 build
sass Resources/Private/Scss/StyleSheet.scss:Resources/Public/Styles/StyleSheet.css && sass --style=compressed Resources/Private/Scss/StyleSheet.scss:Resources/Public/Styles/StyleSheet.min.css

Error: Undefined variable.
╷
51 │ $utilities,
│ ^^^^^^^^^^
╵
Resources/Private/Scss/StyleSheet.scss 51:3 root stylesheet
Failed to run npm run build: exit status 65

Sorry for that, but I have no idea what I am doing wrong or what I have misunderstood.

Maybe you have a tip for me?

Thxx for your work
Best regards,
Paul Bader