On Mon, Nov 01, 2021 at 11:41:58AM +0000, Mark Hindley wrote: > This is documented in Debian's Bullseye Release Notes and referenced from
> Devuan's Chimaera Release Notes.
>
> Mark
The need to upgrade server and client in lockstep is indeed documented
in the Bullseye release notes. I ahve done that.
What is not mentioned is whether the backup archive format has changed
incompatibly.