[GHC] #5721: Panic when quoting a scoped type variable

[GHC]

#5721: Panic when quoting a scoped type variable
--------------------------------+-------------------------------------------
 Reporter:  benmachine          |          Owner:                                         
     Type:  bug                 |         Status:  new                                    
 Priority:  normal              |      Component:  Compiler                               
  Version:  7.2.1               |       Keywords:  template haskell, scoped type variables
       Os:  Unknown/Multiple    |   Architecture:  Unknown/Multiple                       
  Failure:  Compile-time crash  |       Testcase:                                         
Blockedby:                      |       Blocking:                                         
  Related:                      |  
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 {{{
 {-# LANGUAGE TemplateHaskell, ScopedTypeVariables #-}
 module GetNameOfThing where

 import Language.Haskell.TH

 f :: a -> Name
 f (x :: a) = ''a
 }}}
 {{{
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.2.2 for i386-unknown-linux):
         th_bracket a{tv ahF}

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
 }}}
 The function is probably nonsense, but the error message could be
 friendlier.

 Tested on GHC 7.2.2.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5721>
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