问用CSS变量覆盖引导4 Sass变量？

EN

:root {
  --primary: #00695c;
}

$myPrimary: var(--primary);

$primary: $myPrimary; // This does not work

@import '../node_modules/bootstrap/scss/bootstrap';

Failed to compile.

./src/styles.scss (./node_modules/@angular-devkit/build-angular/src/angular-cli-files/plugins/raw-css-loader.js!./node_modules/postcss-loader/src??embedded!./node_modules/sass-loader/lib/loader.js??ref--15-3!./src/styles.scss)
Module build failed (from ./node_modules/sass-loader/lib/loader.js):

undefined
                                         ^
      $color: var(--primary) is not a color.
    ╷
181 │ $link-hover-color:                        darken($link-color, 15%) !default;
    │                                           ^^^^^^^^^^^^^^^^^^^^^^^^
    ╵
  node_modules\bootstrap\scss\_variables.scss 181:43  @import
  node_modules\bootstrap\scss\bootstrap.scss 9:9      @import
  stdin 19:9                                          root stylesheet
      in C:\Work\node_modules\bootstrap\scss\_variables.scss (line 181, column 43)

@import './library-styles-to-be-used-in-app.scss';

:root {
  --primary: #00695c;
  --secondary: #f4f5f6;
}

@import '../dist/library/styles/theme.scss';
@import '../node_modules/bootstrap/scss/bootstrap';