The debdiff patch is in the attachment.I have tested that locally,and it works well.Please let me know whether this solution can be accepted.
You seem to have totally ignored the existing built-using.patch and added a new patch, furthermore your new patch hardcodes the version number of ring, so it will likely break with the next version update. A quick look suggests that upstream has added an extra underscore to the name of the test library, I suspect that all is needed is adding a corresponding underscore to built-using.patch. I will confirm this and make an upload over the next day or so if noone gets there first.
