TcCoercibleFail.hs:11:8: error:
    Couldn't match representation of type ‘Int’ with that of ‘()’
      arising from a use of ‘coerce’
    In the expression: coerce
    In the expression: coerce $ one :: ()
    In an equation for ‘foo1’: foo1 = coerce $ one :: ()

TcCoercibleFail.hs:14:8: error:
    Couldn't match representation of type ‘m Int’ with that of ‘m Age’
      arising from a use of ‘coerce’
    NB: We cannot know what roles the parameters to ‘m’ have;
      we must assume that the role is nominal
    In the expression: coerce
    In the expression: coerce $ (return one :: m Int)
    In an equation for ‘foo2’: foo2 = coerce $ (return one :: m Int)
    Relevant bindings include
      foo2 :: m Age (bound at TcCoercibleFail.hs:14:1)

TcCoercibleFail.hs:16:8: error:
    Couldn't match type ‘Int’ with ‘Age’ arising from a use of ‘coerce’
    In the expression: coerce
    In the expression: coerce $ Map one () :: Map Age ()
    In an equation for ‘foo3’: foo3 = coerce $ Map one () :: Map Age ()

TcCoercibleFail.hs:18:8: error:
    Couldn't match representation of type ‘Int’ with that of ‘Down Int’
      arising from a use of ‘coerce’
    The data constructor ‘Down’ of newtype ‘Down’ is not in scope
    In the expression: coerce
    In the expression: coerce $ one :: Down Int
    In an equation for ‘foo4’: foo4 = coerce $ one :: Down Int

TcCoercibleFail.hs:21:8: error:
    Couldn't match representation of type ‘Void’ with that of ‘()’
      arising from a use of ‘coerce’
    In the expression: coerce :: Void -> ()
    In an equation for ‘foo5’: foo5 = coerce :: Void -> ()

TcCoercibleFail.hs:24:9: error:
    Couldn't match representation of type ‘VoidBad ()’
                             with that of ‘()’
      arising from a use of ‘coerce’
    In the expression: coerce :: (VoidBad ()) -> ()
    In an equation for ‘foo5'’: foo5' = coerce :: (VoidBad ()) -> ()

TcCoercibleFail.hs:28:8: error:
    Reduction stack overflow; size = 201
    When simplifying the following type: Fix (Either Age)
    Use -freduction-depth=0 to disable this check
    (any upper bound you could choose might fail unpredictably with
     minor updates to GHC, so disabling the check is recommended if
     you're sure that type checking should terminate)
    In the expression: coerce :: Fix (Either Int) -> Fix (Either Age)
    In an equation for ‘foo6’:
        foo6 = coerce :: Fix (Either Int) -> Fix (Either Age)

TcCoercibleFail.hs:29:8: error:
    Couldn't match representation of type ‘Either
                                             Int (Fix (Either Int))’
                             with that of ‘()’
      arising from a use of ‘coerce’
    In the expression: coerce :: Fix (Either Int) -> ()
    In an equation for ‘foo7’: foo7 = coerce :: Fix (Either Int) -> ()