I ran into 2 things, likely resulting from differences between Roon Core versioning and ROCK Roon Core Distribution versioning.
The first was FFMPEG. When installing Roon Core on top of your favorite linux distro, you use the distro’s package manager to install the entire FFMPEG package. Life is good.
When installing ROCK, you copy the ffmpeg image (the executable file) to the specified share directory that ROCK exposes. Restarting rock moves the ffmpeg image over the /usr/local/bin or wherever it lives.
The migration instructions need a rewrite to describe the forest before getting procedural. Once I got past the read the instructions to the end before doing anything trick (I remember that one from high school) things went well.
The database restoration procedure was also a bit glitchy. Roon Core and ROCK track versioning differently and the database releases are identified by date cut but not Roon Core code version used or db schema version. So if there was an update recently and Roon Core and ROCK are using different DB schemas, things can get exciting. I had to back up a day or two.
The rough bit is that if ROCK ingests an incompatible db version, there is no clear path to take a mulligan. It took some fumbling around and some looking at date stamps over on the file server where db backups live.
I’m good to go now, but if you’re not computer handy, buy a Nucleus!