[GHC] #7975: "impossible" failure while type checking

[GHC]

#7975: "impossible" failure while type checking
--------------------------------------+-------------------------------------
  Reporter:  jonnadal                 |          Owner:         
      Type:  bug                      |         Status:  closed 
  Priority:  normal                   |      Milestone:         
 Component:  Compiler (Type checker)  |        Version:  7.6.3  
Resolution:  duplicate                |       Keywords:         
        Os:  MacOS X                  |   Architecture:  x86    
   Failure:  Compile-time crash       |     Difficulty:  Unknown
  Testcase:                           |      Blockedby:         
  Blocking:                           |        Related:         
--------------------------------------+-------------------------------------
Changes (by simonpj):

  * status:  new => closed
  * difficulty:  => Unknown
  * resolution:  => duplicate


Comment:

 Thanks.  I'm guessing this is a dup of #7927, #7920, #7905, etc. Works in
 HEAD:
 {{{
 T7975.hs:3:15:
     Couldn't match type ‛m0 (IO ())’ with ‛()’
     Expected type: () -> t1 m0 (IO ())
       Actual type: m0 (IO ()) -> t1 m0 (IO ())
     In the second argument of ‛(.)’, namely ‛lift’
     In the expression: lift . lift
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7975#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler