tcfail190.hs:14:31: error: [GHC-39999]
    • No instance for ‘Ord Unorderable’
        arising from a use of ‘groupWith’
    • In the expression: groupWith
      In a stmt of a list comprehension: then group by x using groupWith
      In the expression:
        [() | x <- [Gnorf, Brain], then group by x using groupWith]