Singletons/Undef.hs:(0,0)-(0,0): Splicing declarations
    singletons
      [d| foo :: Bool -> Bool
          foo = undefined
          bar :: Bool -> Bool
          bar = error "urk" |]
  ======>
    foo :: Bool -> Bool
    foo = undefined
    bar :: Bool -> Bool
    bar = error "urk"
    type BarSym1 (t :: Bool) = Bar t
    instance SuppressUnusedWarnings BarSym0 where
      suppressUnusedWarnings _
        = snd (GHC.Tuple.(,) BarSym0KindInference GHC.Tuple.())
    data BarSym0 (l :: TyFun Bool Bool)
      = forall arg. KindOf (Apply BarSym0 arg) ~ KindOf (BarSym1 arg) =>
        BarSym0KindInference
    type instance Apply BarSym0 l = BarSym1 l
    type FooSym1 (t :: Bool) = Foo t
    instance SuppressUnusedWarnings FooSym0 where
      suppressUnusedWarnings _
        = snd (GHC.Tuple.(,) FooSym0KindInference GHC.Tuple.())
    data FooSym0 (l :: TyFun Bool Bool)
      = forall arg. KindOf (Apply FooSym0 arg) ~ KindOf (FooSym1 arg) =>
        FooSym0KindInference
    type instance Apply FooSym0 l = FooSym1 l
    type family Bar (a :: Bool) :: Bool where
      Bar a_0123456789 = Apply (Apply ErrorSym0 "urk") a_0123456789
    type family Foo (a :: Bool) :: Bool where
      Foo a_0123456789 = Apply Any a_0123456789
    sBar ::
      forall (t :: Bool). Sing t -> Sing (Apply BarSym0 t :: Bool)
    sFoo ::
      forall (t :: Bool). Sing t -> Sing (Apply FooSym0 t :: Bool)
    sBar sA_0123456789
      = let
          lambda ::
            forall a_0123456789. t ~ a_0123456789 =>
            Sing a_0123456789 -> Sing (Apply BarSym0 a_0123456789 :: Bool)
          lambda a_0123456789 = sError (sing :: Sing "urk")
        in lambda sA_0123456789
    sFoo sA_0123456789
      = let
          lambda ::
            forall a_0123456789. t ~ a_0123456789 =>
            Sing a_0123456789 -> Sing (Apply FooSym0 a_0123456789 :: Bool)
          lambda a_0123456789 = undefined
        in lambda sA_0123456789