<===> input.scss
.a {
  b: c;
  d:
}

<===> error
Error: Invalid CSS after "  d:": expected expression (e.g. 1px, bold), was "}"
        on line 4 of input.scss
  Use --trace for backtrace.

<===> error-dart-sass
Error: Expected expression.
  ,
3 |   d:
  |     ^
  '
  input.scss 3:5  root stylesheet