anchor.diff:      Context context, Uri absoluteUri, GltfReaderResult readerResult) {
     // Check file stat to not bother with FileSystem exceptions
     File fileGuarded(Uri uri) {
  -    final f = File.fromUri(absoluteUri.resolveUri(uri));
  +    final f = File(p.fromUri(absoluteUri.resolveUri(uri)));
       if (f.statSync().type == FileSystemEntityType.file) {
         return f;
       } else {
  
positive.code:   final reader = GltfReader.filename(file.openRead(), task.filename, context);
  
    if (reader == null) {
      final ext = path.extension(task.filename).toLowerCase();
      errPipe.write('Error while loading ${file.path}...\n'
          'Unknown file extension `$ext`.\n');
      watch.stop();
  
negative.code: 
      final it = Directory(input).listSync(recursive: true).where((entry) {
        if (entry is File) {
          final ext = p.extension(entry.path);
          return (ext == '.gltf') || (ext == '.glb');
        }
        return false;
  