On the directory

(which is the kernel/sched/ subdirectory from linux 5.9.1) I get the following traceback when trying to scanning with sunburst rendering:

swh scanner scan -f sunburst sched
Traceback (most recent call last):

File "/home/zack/.cache/virtualenvs/t/bin/swh", line 8, in <module>
  sys.exit(main())
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/swh/core/cli/__init__.py", line 185, in main
  return swh(auto_envvar_prefix="SWH")
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/click/core.py", line 1128, in __call__
  return self.main(*args, **kwargs)
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/click/core.py", line 1053, in main
  rv = self.invoke(ctx)
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/click/core.py", line 1659, in invoke
  return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/click/core.py", line 1659, in invoke
  return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/click/core.py", line 1395, in invoke
  return ctx.invoke(self.callback, **ctx.params)
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/click/core.py", line 754, in invoke
  return __callback(*args, **kwargs)
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/click/decorators.py", line 26, in new_func
  return f(get_current_context(), *args, **kwargs)
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/swh/scanner/cli.py", line 188, in scan
  scanner.scan(config, root_path, patterns, out_fmt, interactive, policy, extra_info)
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/swh/scanner/scanner.py", line 101, in scan
  out.show(out_fmt)
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/swh/scanner/output.py", line 50, in show
  sunburst_figure = generate_sunburst(directory_data, self.root_path)
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/swh/scanner/plot.py", line 238, in generate_sunburst
  dirs_df = generate_df_from_dirs(directories, df_columns, max_depth)
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/swh/scanner/plot.py", line 219, in generate_df_from_dirs
  df = pd.DataFrame(
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/pandas/core/frame.py", line 672, in __init__
  mgr = ndarray_to_mgr(
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/pandas/core/internals/construction.py", line 324, in ndarray_to_mgr
  _check_values_indices_shape_match(values, index, columns)
File "/home/zack/.cache/virtualenvs/t/lib/python3.9/site-packages/pandas/core/internals/construction.py", line 389, in _check_values_indices_shape_match
  raise ValueError("Empty data passed with indices specified.")

ValueError: Empty data passed with indices specified.

other output formats work fine, and it is not clear to me what makes this specific directory fail.