[GHC] #10946: Typed hole inside typed Template Haskell bracket causes panic

[GHC]

#10946: Typed hole inside typed Template Haskell bracket causes panic
-------------------------------------+-------------------------------------
           Reporter:  jstolarek      |             Owner:
               Type:  bug            |            Status:  new
           Priority:  high           |         Milestone:  8.0.1
          Component:  Template       |           Version:  7.10.1
  Haskell                            |
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  Compile-time
  Unknown/Multiple                   |  crash
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |
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 When I say:

 {{{#!hs
 m :: a -> a
 m x = $$([||_||])
 }}}
 I get:
 {{{
 T10946.hs:47:13:ghc: panic! (the 'impossible' happened)
   (GHC version 7.10.1 for x86_64-unknown-linux):
         No skolem info: a_apJ[sk]
 }}}
 This happens both with GHC 7.10.1 and latest HEAD
 (e2b579e8d77357e8b36f57d15daead101586ac8e).

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10946>
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