Async Python Actions in Colang Version 2.0

[efrat-deepkeep]

I am trying to follow the documentation for calling an asynchronous function as an action.
Here is the relevant code from the docs:

# in actions.py
from nemoguardrails.actions import action
@action(name="CustomAsyncTestAction", execute_async=True)
async def custom_test(value: int):
    return value + value

# in main.co
import core
flow main
    start CustomAsyncTestAction(value=5) as $action_ref
    await $action_ref.Finished() as $event_ref
    bot say "The result is: {$event_ref.return_value}" # Access the function return value via the event reference

This isn't working for me. I keep getting the following error:
ColangSyntaxError: Unsupported spec type '<class 'nemoguardrails.colang.v2_x.lang.colang_ast.Spec'>'

This is the traceback:

Traceback (most recent call last):
 File ".../bin/nemoguardrails", line 8, in <module>
   sys.exit(app())
 File ".../lib/python3.10/site-packages/typer/main.py", line 328, in __call__
   raise e
 File ".../lib/python3.10/site-packages/typer/main.py", line 311, in __call__
   return get_command(self)(*args, **kwargs)
 File ".../lib/python3.10/site-packages/click/core.py", line 1157, in __call__
   return self.main(*args, **kwargs)
 File ".../lib/python3.10/site-packages/typer/core.py", line 783, in main
   return _main(
 File ".../lib/python3.10/site-packages/typer/core.py", line 225, in _main
   rv = self.invoke(ctx)
 File ".../lib/python3.10/site-packages/click/core.py", line 1688, in invoke
   return _process_result(sub_ctx.command.invoke(sub_ctx))
 File ".../lib/python3.10/site-packages/click/core.py", line 1434, in invoke
   return ctx.invoke(self.callback, **ctx.params)
 File ".../lib/python3.10/site-packages/click/core.py", line 783, in invoke
   return __callback(*args, **kwargs)
 File ".../lib/python3.10/site-packages/typer/main.py", line 683, in wrapper
   return callback(**use_params)  # type: ignore
 File ".../lib/python3.10/site-packages/nemoguardrails/cli/__init__.py", line 95, in chat
   run_chat(
 File ".../lib/python3.10/site-packages/nemoguardrails/cli/chat.py", line 610, in run_chat
   asyncio.run(_run_chat_v2_x(rails_app))
 File ".../lib/python3.10/asyncio/runners.py", line 44, in run
   return loop.run_until_complete(main)
 File ".../lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
   return future.result()
 File ".../lib/python3.10/site-packages/nemoguardrails/cli/chat.py", line 497, in _run_chat_v2_x
   await _process_input_events()
 File ".../lib/python3.10/site-packages/nemoguardrails/cli/chat.py", line 439, in _process_input_events
   output_events, output_state = await rails_app.process_events_async(
 File ".../lib/python3.10/site-packages/nemoguardrails/rails/llm/llmrails.py", line 973, in process_events_async
   output_events, output_state = await self.runtime.process_events(
 File ".../lib/python3.10/site-packages/nemoguardrails/colang/v2_x/runtime/runtime.py", line 436, in process_events
   initialize_state(state)
 File ".../lib/python3.10/site-packages/nemoguardrails/colang/v2_x/runtime/statemachine.py", line 94, in initialize_state
   initialize_flow(state, flow_config)
 File ".../lib/python3.10/site-packages/nemoguardrails/colang/v2_x/runtime/statemachine.py", line 112, in initialize_flow
   flow_config.elements = expand_elements(flow_config.elements, state.flow_configs)
 File ".../lib/python3.10/site-packages/nemoguardrails/colang/v2_x/lang/expansion.py", line 71, in expand_elements
   expanded_elements = _expand_await_element(element)
 File ".../lib/python3.10/site-packages/nemoguardrails/colang/v2_x/lang/expansion.py", line 478, in _expand_await_element
   raise ColangSyntaxError(f"Unsupported spec type '{type(element.spec)}'")
nemoguardrails.colang.v2_x.runtime.errors.ColangSyntaxError: Unsupported spec type '<class 'nemoguardrails.colang.v2_x.lang.colang_ast.Spec'>'

How can I fix this?
Any help would be greatly appreciated!