[GHC] #6015: "No instance" when using PolyKinds/DataKinds/FunDeps/Undecidable

[GHC]

#6015: "No instance" when using PolyKinds/DataKinds/FunDeps/Undecidable
---------------------------------+------------------------------------------
    Reporter:  atnnn             |       Owner:                           
        Type:  feature request   |      Status:  new                      
    Priority:  normal            |   Milestone:                           
   Component:  Compiler          |     Version:  7.4.1                    
    Keywords:                    |          Os:  Unknown/Multiple         
Architecture:  Unknown/Multiple  |     Failure:  GHC rejects valid program
  Difficulty:  Unknown           |    Testcase:                           
   Blockedby:                    |    Blocking:                           
     Related:                    |  
---------------------------------+------------------------------------------
Changes (by simonpj):

  * difficulty:  => Unknown


Comment:

 That's odd.  Even with `PolyKinds` on the program typechecks for me.  Are
 you using the latest HEAD?

 But still there's a bug in 6015, and I think I know what it is.  I'll try
 to fix it today.

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/6015#comment:2>
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