<===> input.scss
$map: 1 + (a:b,c:d);

<===> error
Error: (a: b, c: d) isn't a valid CSS value.
        on line 1 of /sass/spec/libsass-issues/issue_2147/input.scss
  Use --trace for backtrace.

<===> error-dart-sass
Error: (a: b, c: d) isn't a valid CSS value.
  ,
1 | $map: 1 + (a:b,c:d);
  |       ^^^^^^^^^^^^^
  '
  input.scss 1:7  root stylesheet