Migration

The migration uses the 2.6 branch of Migrate.

Testing rollbacks

Entities that use Inline Entity Forms (Data sets to Data sources) will likely delete the child entity (the Data sources) when the parent (the Data set) is deleted. For this reason, when rolling back migrated data sets, you also need to roll back the migrated data sources. If you do not roll back data sources, on the next data set import, those relationships will be empty since Migrate assumes the data sources still exist, and tried to link them when the data sources were removed by the Field Referenced Delete module during the data set rollback.