RFC: finish_command_continuation and errors

[Joel Brobecker]

> It seems to me that, abstractly, observers should not be allowed to
> throw exceptions.  Perhaps the observer machinery itself ought to catch
> them.  My reasoning is that letting an observer throw an exception will
> make the observer mechanism apparently unreliable: a given observer
> might or might not be called, depending on whether some earlier observer
> encountered an error.

I think this makes sense.

-- 
Joel