1<===> input.scss
2@mixin bar() {
3  @at-root { @content; }
4}
5
6.test {
7  @include bar() {
8    color: yellow;
9    .nest2 {
10      color: green;
11    }
12  }
13}
14
15<===> error
16Error: Properties are only allowed within rules, directives, mixin includes, or other properties.
17        on line 7 of input.scss
18  Use --trace for backtrace.
19
20<===> error-dart-sass
21Error: Declarations may only be used within style rules.
22  ,
237 |     color: yellow;
24  |     ^^^^^^^^^^^^^
25  '
26  input.scss 7:5   @content
27  input.scss 2:14  bar()
28  input.scss 6:3   root stylesheet
29