Hey, thanks for following up. I have the drivers installed normally. I tried switching to the 387 drivers from 384, which crashed my system.
After reboot, I can’t open Darktable anymore. It says “an error has occurs while trying to open the database […] the database lock file contains a pid that seems to be alive in your system: 3” After deleting the options folder, I’m back to the same issue - no OpenCL.
Googling NVidia drivers and flatpak doesn’t tell me how to install them using flatpak.
I’ll go back to Darktable 2.2 until there’s a PPA for 17.04 or I have time to switch to Linux Mint. :-/