anchor.diff:        relative(cssFile.path, from: dir.path)
       ]..addAll(sasscArgs);
       cmd = [sasscPath]..addAll(args);
  -
       var result = await Process.run(sasscPath, args, workingDirectory: dir.path);
   
       var messages = <SassMessage>[];
  
positive.code: 
        if (file == basename(sassId.path)) {
          int column = arrow.length;
          var start = computeSourceSpan(await sassContent, '$sassId', line, column);
          var span;
          if (start != null) {
            var end = new SourceLocation(
  
negative.code:   throw new StateError("No such position in file: line $line, column $column");
  }
  
  String _resolveEnvVars(String s) =>
      s.replaceAllMapped(
          new RegExp(r'\$\{([^}]+)\}'),
          (Match m) => (Platform.environment[m.group(1)] ?? ''));
  
  // _normalize(String path) {
  //   while (true) {
  //     var newPath = path.replaceAll(new RegExp(r'\.\./\.?[^./]+/|(^|/)\./'), '');
  