tcIfaceCo (IfaceCoConApp tc ts) = tcIfaceCoApp tc ts
tcIfaceCo (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' ->
mkForAllCo tv' <$> tcIfaceCo t
-tcIfaceCo (IfacePredTy co) = mkPredCo <$> tcIfacePred tcIfaceCo co
+-- tcIfaceCo (IfacePredTy co) = mkPredCo <$> tcIfacePred tcIfaceCo co
+tcIfaceCo (IfacePredTy _) = panic "tcIfaceCo"
tcIfaceCoApp :: IfaceCoCon -> [IfaceType] -> IfL Coercion
tcIfaceCoApp IfaceReflCo [t] = Refl <$> tcIfaceType t