Crash when printing function value in asynchronous on-demand evaluation

texts session -a -d  # the same with "texts session -r -d"
Input > use len from builtins
Input > mean(x) = (sum(x)/len(x))
Input > mean((s: 1))
Exiting
Traceback (most recent call last):
  File "vre-language/src/virtmat/language/utilities/errors.py", line 306, in wrapper
    return func(*args, **kwargs)
  File "vre-language/src/virtmat/language/interpreter/session_manager.py", line 164, in get_model_value
    return getattr(self.session.get_model(*args, uuid=self.uuid, **kwargs), 'value', '')
  File "vre-language/src/virtmat/language/interpreter/session.py", line 151, in get_model
    self.process_models(model_str, model_path, active_uuid=uuid)
  File "vre-language/src/virtmat/language/interpreter/session.py", line 240, in process_models
    model, uuid = self._process_model(uuid, strn, path, active_uuid=active_uuid)
  File "vre-language/src/virtmat/language/interpreter/session.py", line 602, in _process_model
    self.wfe.nodes_torun = list(set(self.wfe.nodes_torun+model.fw_ids_torun))
  File "vre-language/src/virtmat/language/interpreter/workflow_executor.py", line 403, in get_fw_ids_torun
    fw_ids.extend(self.lpad.get_fw_ids({'name': var.__fw_name}))
AttributeError: 'Series' object has no attribute '__fw_name'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "vre-language/src/virtmat/language/utilities/errors.py", line 306, in wrapper
    return func(*args, **kwargs)
  File "vre-language/src/virtmat/language/interpreter/session_manager.py", line 184, in process_input
    output = self.get_model_value(model_str=f'print({input_str})')
  File "vre-language/src/virtmat/language/utilities/errors.py", line 341, in wrapper
    raise RuntimeError('non-handled exception') from err
RuntimeError: non-handled exception

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "vre-language/src/virtmat/language/utilities/errors.py", line 306, in wrapper
    return func(*args, **kwargs)
  File "vre-language/src/virtmat/language/cli/run_session.py", line 98, in main
    mgr.main_loop()
  File "vre-language/src/virtmat/language/interpreter/session_manager.py", line 143, in main_loop
    self.interact(banner='Welcome to textS/textM. Type %help for some help.',
  File "/usr/lib64/python3.9/code.py", line 232, in interact
    more = self.push(line)
  File "/usr/lib64/python3.9/code.py", line 258, in push
    more = self.runsource(source, self.filename)
  File "vre-language/src/virtmat/language/interpreter/session_manager.py", line 155, in runsource
    need_inp = self.process_input(source)
  File "vre-language/src/virtmat/language/utilities/errors.py", line 341, in wrapper
    raise RuntimeError('non-handled exception') from err
RuntimeError: non-handled exception

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "vre-language/src/virtmat/language/utilities/errors.py", line 306, in wrapper
    return func(*args, **kwargs)
  File "vre-language/src/virtmat/language/cli/__init__.py", line 38, in texts
    clargs.func(clargs)
  File "vre-language/src/virtmat/language/utilities/errors.py", line 341, in wrapper
    raise RuntimeError('non-handled exception') from err
RuntimeError: non-handled exception

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "jupyter-tensorflow-2023-10-10/bin/texts", line 8, in <module>
    sys.exit(texts())
  File "vre-language/src/virtmat/language/utilities/errors.py", line 341, in wrapper
    raise RuntimeError('non-handled exception') from err
RuntimeError: non-handled exception