[GHC] #13640: Core lint error with deferred type holes

[GHC]

#13640: Core lint error with deferred type holes
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

@@ -0,0 +1,2 @@
+ The following program (note the `-dcore-lint`)
+
@@ -15,0 +17,5 @@
+
+ produces a `*** Core Lint errors : in result of Desugar (after
+ optimization) ***`, more information in attached
+ [https://ghc.haskell.org/trac/ghc/attachment/ticket/13640/tN4R.log the
+ log].

New description:

 The following program (note the `-dcore-lint`)

 {{{#!hs
 {-# Options_GHC -dcore-lint -fdefer-typed-holes #-}

 import Prelude hiding ((.))

 class Functor' f where
   map' :: (a -> b) -> f a -> f b

 class Bifunctor' f where
   map2' :: (a -> b) -> f a c -> f b c

 bimap' :: Bifunctor' f => (a -> b) -> (c -> d) -> (f a c -> f b d)
 bimap' f g = map2' f . map'
 }}}

 produces a `*** Core Lint errors : in result of Desugar (after
 optimization) ***`, more information in attached
 [https://ghc.haskell.org/trac/ghc/attachment/ticket/13640/tN4R.log the
 log].

--

Comment (by Iceland_jack):

 Replying to [comment:1 simonpj]:
 > Can you update the description to explain what the problem is?

 Edited. It seems to have been solved already, thanks for a swift response

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13640#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler