Apparent data corruption on openSUSE:Factory

After build-compare a couple of days ago, ocaml-ppxlib is now the second case where a pkg in the devel prj and openSUSE:Factory got out of sync for no obvious reason. Does anyone happen to know the details about "service error: bad link: conflict in file _service"? Are there any logs on the server that help to understand when and how the corruption happened? How can such corruption prevented in the future? In case of ocaml-ppxlib, I still had a copy from 'osc up -u', which turned out to be identical to the result from 'osc co -u openSUSE:Factory'. Thanks, Olaf