cannot delete group when provisioning configured with roles

It looks like there might be a bug in the new functionality to provision Grouper privileges using
provisioner.ed_group_prov.targetGroupAttribute.1.translateExpression = \u0024{provisioningGroupWrapper.thisGroupPrivilegeHolders(<privilege>, 'subjectId')}
We are running Grouper 4.12.0
The management of the privileges works quite well. However a group can not be deleted.
@mchyzer
 Thank you very much for this enhancement. Sorry that I didn't think to try a group delete until now.
Details:
Selecting action 'Delete group' in the UI results in an error being displayed and does not delete the group.