It appears Linux root-on-ZFS is a mess. No standard way to do it. Kernel updates require recompiling ZFS. Boot environments are a cornucopia of constantly evolving hacks.
If you're actually using #ZFS on root, on #Debian, what's your preferred hack to make that happen? #sysadmin
I suspect #openzfsmastery might need to assume root on extFS and data on ZFS, leaving root-on-ZFS for the advanced user or a terminal chapter. 
@mwl I compile my own ZFS kernel module + userspace packages from source for every specific kernel, then I pin the kernel.
Yes, I've documented how to do this. Yes, it's online.
This sent me looking to your blog, of course. After seeing your latest post I'd like to say: you saying you like my books is especially meaningful, because I know you'll say when you don't like a book. 
@mwl Oh dear. I don't know what you saw.
I have a number of ZFS-on-root tutorials for a few different Linux distributions on my old blog, at least one for Void Linux IIRC, but these days I have scripts to do it for me.
I followed your profile, xenotrope.blogspot.com. ;-)
thanks for the link, I like scripts!
Michael W Lucas 
Toby