Is the ghc ppa needed past 12.04LTS? Past that version, they seem to have ghc 7.6.3 or newer, which is the current target version as it's the version in debian stable. If only specific ubuntu versions need the ghc ppa it would be best to avoid using it on newer ones.

Oh! I hadn't realized 7.6.3 was the target, so I upgraded to 7.10.3 (which is what I've been using for things). I can definitely try a spin without it. I can't remember why I thought 7.6.3 was failing there but I'll definitely dig into it.

Even type aliases would be an improvement but probably newtypes or ADTs would improve on it. Also there may be some overlap with typees in Propellor.Property.Firewall

Oh yes, definitely. I'll take a pass at that too, and dig into Firewall to see what's there.

Isn't Property HasInfo a shorter way to write that? I'm somewhat surprised you arrived at the partially applied type family there; ghc normally tells you the simplified type.

CombinedType (Property NoInfo) (Property HasInfo)

That's an excellent question. I think ultimately I tried a type hole to find out what I was missing, and that's what it came up with, but it also might be differences in ghc versions I stumbled into. I'll give it a try with 7.6.3. I'm using Trusty 14.04.4 for the project this is for.