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+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 3"""
+ date="2015-11-12T16:05:44Z"
+ content="""
+Ok, what's going on is that the combination of a RevertableProperty and a
+Property with requires has changed from being a RevertableProperty before
+to a Property now. (Because it can't all be reverted.)
+Since your code has `schroot :: RevertableProperty HasInfo`
+ghc complains that the type it infers doesn't match. Changing that to
+`Property HasInfo` will clear up the type error.
+Unfortunate that the error message is complicated in this case by the
+use of CInfo and CombinedType. If you notice that
+`CInfo HasInfo NoInfo = HasInfo` and that `CombinedType (RevertableProperty
+HasInfo) (Property NoInfo) = Property HasInfo`, a better error message
+would be:
+ Couldn't match type ‘Property HasInfo'
+ with ‘RevertableProperty HasInfo’
+ Expected type: RevertableProperty HasInfo
+ Actual type: Property HasInfo