"sourceAttributeID was not specified but is required"

[Cantor, Scott]

> We have a couple of attributes that are aggregates of other attributes,
> instead of using an attribute from a specific data source.  We the warning
> "sourceAttributeID was not specified but is required".

It's telling you you're doing something that may accidentally work but is relying on questionable assumptions about how dependencies work. It only gets output for plugin types that implicitly can really only depend on a single source attribute and will behave unpredictably with a dependency on multiple attributes.

By definition if the definition is an aggregate of others, it shouldn't be of a type that intrinsically can only operate on one. If you're doing something fishy like counting on only one of two dependencies to supply a value (I have a case like that), then you have to decide how safe you think that is, and the warning is just responding to that fact.

-- Scott