<===> input.scss
foo {
  bar: #{};
}

<===> error
Error: Invalid CSS after "  bar: #{": expected expression (e.g. 1px, bold), was "};"
        on line 2 of input.scss
  Use --trace for backtrace.

<===> error-dart-sass
Error: Expected expression.
  ,
2 |   bar: #{};
  |        ^^
  '
  input.scss 2:8  root stylesheet