GHCi leaky abstraction: error message mentions `ghciStepIO`
$ ghci -fdefer-type-errors -ignore-dot-ghci
GHCi, version 7.10.0.20150316: http://www.haskell.org/ghc/ :? for help
Prelude> _
<interactive>:2:1: Warning:
Found hole ‘_’ with type: IO t0
Where: ‘t0’ is an ambiguous type variable
In the first argument of ‘GHC.GHCi.ghciStepIO ::
IO a_aly -> IO a_aly’, namely
‘_’
In a stmt of an interactive GHCi command:
it <- GHC.GHCi.ghciStepIO :: IO a_aly -> IO a_aly _
*** Exception: <interactive>:2:1:
Found hole ‘_’ with type: IO t0
Where: ‘t0’ is an ambiguous type variable
In the first argument of ‘GHC.GHCi.ghciStepIO ::
IO a_aly -> IO a_aly’, namely
‘_’
In a stmt of an interactive GHCi command:
it <- GHC.GHCi.ghciStepIO :: IO a_aly -> IO a_aly _
(deferred type error)
Prelude>
It should ideally not expose ghciStepIO
to the user.