DNG custom attributes do not appear in report builder until artifacts are created

When you create a new custom attribute to a work item type in RTC, it will immediately become available in the "Set conditions" section under "CHOOSE DATA" in report builder.

You don't have to create a work item. You don't even have to add it to a work item presentation -- just add a new custom attribute to the list of attributes for a work item.

But when you create a new artifact type, or create a new attribute type and add it to an artifact type in DNG, the same attribute is not displayed in report builder.

We gave an attribute a default value in the DNG project properties, and then added it to an existing artifact type, but it is only when you create an actual artifact which uses that attribute that the attribute appears in report builder under e.g. the "Set conditions" section.

This seems to be due to the defect tracked here:

DNG reporting REST APIs do not reflect CRUD operations for DNG types (127238)
https://jazz.net/jazz03/resource/itemName/com.ibm.team.workitem.WorkItem/127238

But an enhancement for the reporting REST API is needed to resolve that.

Could you implement the enhancement, so that this might be done?

The issue appears to be due to related to how DNG presents the data for the ETL. DNG provides all data in one feed, for collections, modules and requirements, then DCC parses the feed and extracts the data to put is in the different tables. This is why a custom attributes needs to be associated to a requirement for it to be collected.
Since the feed presents new and updated artifacts, creating a new requirement generates an entry in the feed, and also modifying an existing one.