Idris 1.2.0 can not infer type of tuple in Dependent Pair

type-infer-problem-in-dependent-pair.idr

data Color = Red | Blue
data Size = S | M | L

data Ball : (c : Color) -> (s : Size) -> Type where
  MkRedSBall : Ball Red S
  MkRedMBall : Ball Red M

arr : List (c : Color ** s : Size ** Ball c s)
arr = [(Red ** S ** MkRedSBall), (Red ** M ** MkRedMBall)]

arr' : List (c : Color ** s : Size ** Ball c s)
arr' = [(_ ** _ ** MkRedSBall), (_ ** _ ** MkRedMBall)]

arr2 : List (cs : (Color, Size) ** Ball (fst cs) (snd cs))
arr2 = [((Red, S) ** MkRedSBall), ((Red, M) ** MkRedMBall)]

arr2' : List (cs : (Color, Size) ** Ball (fst cs) (snd cs))
arr2' = [((_, _) ** MkRedSBall), ((Red, M) ** MkRedMBall)]

-- failed to infer type of _
--arr2'' : List (cs : (Color, Size) ** Ball (fst cs) (snd cs))
--arr2'' = [(_ ** MkRedSBall), ((Red, M) ** MkRedMBall)]

-- failed to parse pattern-matching-style in '**' syntax
--arr3 : List ((c : Color, s : Size) ** Ball c s)
--arr3 = [((Red, S) ** MkRedSBall), ((Red, M) ** MkRedMBall)]