#7560: Panic in conflictInstErr when branched type family instances conflict
Reporter:  goldfire            |          Owner:  goldfire        
    Type:  bug                 |         Status:  new             
Priority:  normal              |      Component:  Compiler        
 Version:  7.7                 |       Keywords:  TypeFamilies    
      Os:  Unknown/Multiple    |   Architecture:  Unknown/Multiple
 Failure:  Compile-time crash  |      Blockedby:                  
Blocking:                      |        Related:                  
 This code causes the panic:

 {-# LANGUAGE TypeFamilies #-}

 type family F a

 type instance where
   F Int = Int
   F Bool = Bool

 type instance where
   F Int = Char
   F Double = Double

 Here is the output:
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.7.20121221 for x86_64-apple-darwin):
 <<details unavailable>>

 Fix on the way...

Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7560>
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