[GHC] #5001: makeCorePair: arity missing

[GHC]

#5001: makeCorePair: arity missing
-------------------------------------+-------------------------------------
        Reporter:  maeder            |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  high              |               Milestone:  7.4.1
       Component:  Compiler          |                 Version:  7.2.1
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Incorrect         |               Test Case:
  warning at compile-time            |  deSugar/should_compile/T5001
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Comment (by thomie):

 Here is a test to reproduce the problem from comment:21.

 {{{#!haskell
 {-# LANGUAGE DefaultSignatures #-}
 module T5001b where

 class GEnum a where
     genum :: [a]
     default genum :: [a]
     genum = undefined

 instance GEnum Int where
     {-# INLINE genum #-}
 }}}

 {{{
 $ ghc-7.10.2 T5001b.hs
 [1 of 1] Compiling T5001b           ( T5001b.hs, T5001b.o )
 makeCorePair: arity missing $cgenum_am5
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5001#comment:23>
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