how to communicate why an action's goal has not been accepted (ros2)?

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Hi everyone,

I hope someone can shed some light into this: is there a way to communicate to the client why a goal has not been accepted?

AFAIK there is no message field or similar to do so, like it is done in the examples of action or service servers. There the reason for a failed action or service is passed on to the client with such message field.

Or is it common to blindly accept it and then to check in the execute_callback whether it is possible to process it, else to cancel or abort it and passed the reason in the Result object?

I'll appreciate any input!