[GHC] #8368: Panic in rejigConRes

[GHC]

#8368: Panic in rejigConRes
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       Reporter:  goldfire          |             Owner:  goldfire
           Type:  bug               |            Status:  new
       Priority:  normal            |         Milestone:
      Component:  Compiler          |           Version:  7.7
       Keywords:                    |  Operating System:  Unknown/Multiple
   Architecture:  Unknown/Multiple  |   Type of failure:  None/Unknown
     Difficulty:  Unknown           |         Test Case:
     Blocked By:                    |          Blocking:
Related Tickets:                    |
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 When I compile the following erroneous code

 {{{
 {-# LANGUAGE DataKinds, TypeFamilies, GADTs #-}

 import GHC.TypeLits

 data Foo = Bar

 data instance Sing (n :: Foo) where
   SBar :: Sing Foo
 }}}

 I get

 {{{
 *** Exception: compiler/typecheck/TcTyClsDecls.lhs:1266:5-62: Irrefutable
 pattern failed for pattern Data.Maybe.Just subst
 }}}

 I think this is my fault. I will fix.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8368>
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