Taking a look right now. At first glance, this looks like an issue causing some or all of the backup files to not be written properly to the S3 buckets (so issues during the restore are expected). We have customers that have successfully done backups in S3 and system tests that are passing so hopefully this is just some kind of configuration issue that can be resolved without having to release a new version of Dgraph.
In the meantime, I just want to point out that we support exporting Dgraph data to RDF or JSON, so there’s an alternative way to backup data. It’s got the disadvantage that there’s no incremental update support but hopefully it’s good enough to unblock your production release if it comes to that.
I’ll take a deeper look and reply again with more info and/or requests.