[GHC] #11742: 'Strict' extension is incompatible with 'deriving' mechanism

22 Mar 2016


      #11742: 'Strict' extension is incompatible with 'deriving' mechanism
-------------------------------------+-------------------------------------
           Reporter:  awson          |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 This:
 {{{#!hs
 {-# LANGUAGE Strict #-}

 module Foo where

 data Foo = Foo deriving Eq
 }}}
 panics with
 {{{
 ghc.EXE: panic! (the 'impossible' happened)
   (GHC version 8.1.20160317 for x86_64-unknown-mingw32):
         makeCorePair: dfun $dEq_a1zL
 }}}

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Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11742
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