Bug#818050: /usr/bin/colormgr: cannot profile monitor with gretag i1-display2

[Christopher James Halse Rogers]

Hm. I see that you don't have colord-sensor-argyll installed. I think 
that might be required to drive your calibration device.

Can you please try installing it and see if calibration works?
It's a Suggests: rather than a Recommends: because it depends on 
argyll, which is almost 100MB on-disc and is not necessary for quite a 
lot of users, but we could certainly fix the error reported.