<===> input.scss
foo {
    color: missing($a: b);
}

<===> error
Error: Plain CSS function missing doesn't support keyword arguments
        on line 2 of input.scss
  Use --trace for backtrace.

<===> error-dart-sass
Error: Plain CSS functions don't support keyword arguments.
  ,
2 |     color: missing($a: b);
  |            ^^^^^^^^^^^^^^
  '
  input.scss 2:12  root stylesheet