[GHC] #5770: Non-sensical error message when compiling with PolyKinds and a type family

[GHC]

#5770: Non-sensical error message when compiling with PolyKinds and a type family
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    Reporter:  goldfire                 |       Owner:  dreixel                  
        Type:  bug                      |      Status:  new                      
    Priority:  high                     |   Milestone:  7.4.1                    
   Component:  Compiler (Type checker)  |     Version:  7.4.1-rc1                
    Keywords:  PolyKinds                |          Os:  Unknown/Multiple         
Architecture:  Unknown/Multiple         |     Failure:  GHC rejects valid program
  Difficulty:  Unknown                  |    Testcase:                           
   Blockedby:                           |    Blocking:                           
     Related:                           |  
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Changes (by igloo):

  * owner:  => dreixel
  * difficulty:  => Unknown
  * priority:  normal => high
  * milestone:  => 7.4.1


Comment:

 Thanks for the report. dreixel, if this is easy to fix we may as well get
 it into 7.4.1, although it's not actually a regression as PolyKinds? is
 new.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5770#comment:2>
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