testsuite/tests/deriving/should_fail/T7148.stderr


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T7148.hs:27:40:
    Could not coerce from ‛SameType b1 b’ to ‛SameType b1 (Tagged a b)’
      because the second type argument of ‛SameType’ has role Nominal,
      but the arguments ‛b’ and ‛Tagged a b’ differ
      arising from the 'deriving' clause of a data type declaration
    Possible fix:
      use a standalone 'deriving instance' declaration,
        so you can specify the instance context yourself
    When deriving the instance for (IsoUnit (Tagged a b))

T7148.hs:27:40:
    Could not coerce from ‛SameType b b1’ to ‛SameType (Tagged a b) b1’
      because the first type argument of ‛SameType’ has role Nominal,
      but the arguments ‛b’ and ‛Tagged a b’ differ
      arising from the 'deriving' clause of a data type declaration
    Possible fix:
      use a standalone 'deriving instance' declaration,
        so you can specify the instance context yourself
    When deriving the instance for (IsoUnit (Tagged a b))