There are a lot of old snapshots https://repository.apache.org/content/groups/snapshots/org/apache/jena/
Most some maven files left over (md5, sha1), some directories have artifacts in.
It doesn't seem possible to delete them all via the Nexus server except one-by-one.
I'll file a ticket asking INFRA to delete everything from the root as being simplest way to clear-up, and we can rebuild 4.8.0-SNAPSHOT again.
Andy
