T8616.hs:8:30: error:
    • Expected a type, but ‘Any :: k’ has kind ‘k’
      ‘k’ is a rigid type variable bound by
        the type signature for:
          withSomeSing :: forall k (kproxy :: k). Proxy kproxy
        at T8616.hs:7:1-52
    • In an expression type signature: (Any :: k)
      In the expression: undefined :: (Any :: k)
      In an equation for ‘withSomeSing’:
          withSomeSing = undefined :: (Any :: k)
    • Relevant bindings include
        withSomeSing :: Proxy kproxy (bound at T8616.hs:8:1)