Actually, I spoke too fast :
I redid everything on a clean system, and using your PPA was not enough.
Here is the full list of commands that worked :
```
sudo add-apt-repository ppa:jonathonf/zfs
sudo apt update
git clone https://github.com/nathmo/makeZFS_armbian
cd makeZFS_armbian
sudo python3 makeZFS_armbian.py
sudo apt install zfs-dkms zfs-zed zfsutils-linux
```
(the whole RockPro64 NAS setup is on github (i'm not allow to paste the link nor modify my previous post. Sorry about that)
if of any use to someone : nathmo/makeZFS_armbian)
I Had to fork from the original script to fix a broken tab and the python version that was deprecated.
I also document the rest of the instruction to duplicate my setup