testsuite/tests/deriving/should_fail/T3833.stderr


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T3833.hs:9:1:
    Can't make a derived instance of ‘Monoid (DecodeMap e)’:
      ‘Monoid’ is not a derivable class
      Try GeneralizedNewtypeDeriving for GHC's newtype-deriving extension
    In the stand-alone deriving instance for ‘Monoid (DecodeMap e)’