[GHC] #10045: type holes related ghc panic

[GHC]

#10045: type holes related ghc panic
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              Reporter:  pacak       |             Owner:
                  Type:  bug         |            Status:  new
              Priority:  normal      |         Milestone:
             Component:  Compiler    |           Version:  7.10.1-rc2
              Keywords:              |  Operating System:  Unknown/Multiple
          Architecture:              |   Type of failure:  Compile-time
  Unknown/Multiple                   |  crash
             Test Case:              |        Blocked By:
              Blocking:              |   Related Tickets:
Differential Revisions:              |
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 {{{
 sample.hs:9:13:
     Couldn't match expected type ‘t’ with actual type ‘()’
       ‘t’ is untouchable
         inside the constraints ()
         bound by the inferred type of foo :: Meta -> t1
         at sample.hs:(6,1)-(9,17)ghc: panic! (the 'impossible' happened)
   (GHC version 7.10.0.0 for x86_64-unknown-linux):
         No skolem info: t_avJ[sk]

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug


 sample.hs:
 module Blah where

 newtype Meta = Meta ()

 foo (Meta ws1) =
     let copy :: _
         copy w from = copy w 1
     in copy ws1 1
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10045>
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