Well, both, actually ;-)

I have some code where I use error with a struct input, and I was surprised to discover that my code behaved differently in Matlab and in Octave.

It took me some time to realize that the stack field was simply ignored by Octave.  In fact, the documentation for 'error' does not even mention the case where error is called with a struct input.

So, yes, I was mainly recording this in the tracker to make it easier for people to find this information.

But of course I would be happy if someone could tackle the issue. It has been there for such a long time, I assume it must not be bothering too many people...

The error () function, when called with a struct input argument, ignores the 'stack' field.

There is a comment about that in libinterp/corefcn/error.cc:

// FIXME: also need to handle "stack" field in error structure,
//        but that will require some more significant surgery on
//        handle_message, error_with_id, etc.