Comment # 16 on bug 1228659 from Richard Brown

> 
> * libsystemd v255 instead of v256
> 
> It is present in some systems, and not in others. I do not see it in this
> bug report log.
> 
> * No ESP detected. Legacy system?
> 
> That is sdbootutil complaining when boot_root cannot be found. I am trying
> to reproduce this one, and can be related with systemd 256 update, as is
> fetched from bootctl.
> 
> I can focused in this last one.

In my situation both of the above quoted issues were resolved by first updating
systemd & systemd-boot, then rebooting, then doing a dup with everything else

So it might not be worthwhile trying to split the baby but could make sense to
consider the issues interlinked 

As Thorsten cannot fix his issue with a workaround I’m going to ask - can you
provide a log of your failing transactional-updates?