drvfail015.hs:10:19:
    Illegal instance declaration for ‛Eq T’
      (All instance types must be of the form (T t1 ... tn)
       where T is not a synonym.
       Use TypeSynonymInstances if you want to disable this.)
    In the stand-alone deriving instance for ‛Eq T’

drvfail015.hs:13:1:
    Can't make a derived instance of ‛Eq Handle’:
      The data constructors of ‛Handle’ are not all in scope
        so you cannot derive an instance for it
    In the stand-alone deriving instance for ‛Eq Handle’