Re: [GHC] #14326: Panic on COMPLETE pragma with mismatched type variable order

5 Oct 2017

      #14326: Panic on COMPLETE pragma with mismatched type variable order
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        Reporter:  dailectic         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by RyanGlScott):

 I feel like you're leaving out some important information here. I tried
 loading this file (I had to add some language extensions that you left
 out):

 {{{#!hs
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 module Bug where

 data E a b = L' a | R b
 pattern L :: forall b a. a -> E a b
 pattern L a = L' a
 {-# COMPLETE L, R #-}
 }}}

 I compiled this with 8.2.1, but it did not panic. What am I missing?

-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14326#comment:1
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