Build Fix

generator/__main__.py

@@ -57,6 +57,8 @@ def generate_assets(args: argparse.Namespace) -> None:
 
   report('checking source paths')
   for source in sorted(data_dir.rglob('*.xml')):
+    if source.is_relative_to(data_dir / 'rhythms'):
+      continue
     if source.parent not in (data_dir / 'practice', data_dir / 'songs'):
       raise ValueError(f'{source}: MusicXML sources belong directly under data/practice or data/songs')
   source_paths(data_dir / 'songs')