GHC panic when used with deferred type errors, again
Similar to previous report of mine #9834 (closed). Given error.hs
data I a = I a
I get the following result:
$ ghci -fdefer-type-errors -ignore-dot-ghci error.hs
GHCi, version 7.10.0.20150316: http://www.haskell.org/ghc/ :? for help
[1 of 1] Compiling Main ( error.hs, interpreted )
Ok, modules loaded: Main.
*Main> I <$> _
I <$> _
<interactive>:2:7: Warning:
Found hole ‘_’ with type: IO a0
Where: ‘a0’ is an ambiguous type variable
In the second argument of ‘(<$>)’, namely ‘_’
In the first argument of ‘GHC.GHCi.ghciStepIO ::
IO a_auR -> IO a_auR’, namely
‘I <$> _’
In a stmt of an interactive GHCi command:
it <- GHC.GHCi.ghciStepIO :: IO a_auR -> IO a_auR (I <$> _)
ghc: panic! (the 'impossible' happened)
(GHC version 7.10.0.20150316 for i386-unknown-linux):
nameModule $dShow_aIT
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
*Main>