I faced a similar issue during one of the transfers. On investigating, it turned out to be a disk space issue, since, there wasn't enough free space in the target instance, it was leading to this error. On clearing up some space by removing some stale or unwanted files, I was able to rectify this issue, hence, would like to point this out for reference during future instances.
Thanks for sharing your finding. I've seen this before too.
I have added this to the documentation: