[GHC] #11442: Segfault when showing (undefined :: Type)

[GHC]

#11442: Segfault when showing (undefined :: Type)
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:  duplicate         |             Keywords:
Operating System:  Linux             |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  crash                              |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Description changed by Iceland_jack:

@@ -1,3 +1,3 @@
- This [https://ghc.haskell.org/trac/ghc/ticket/11311?replyto=3#comment:3
- comment] made me wonder about the relationship between `Void` and `Type`,
- `id :: Void -> Void` and `id :: Type -> Type`:
+ This [https://ghc.haskell.org/trac/ghc/ticket/11311#comment:3 comment]
+ made me wonder about the relationship between `Void` and `Type`, `id ::
+ Void -> Void` and `id :: Type -> Type`:

New description:

 This [https://ghc.haskell.org/trac/ghc/ticket/11311#comment:3 comment]
 made me wonder about the relationship between `Void` and `Type`, `id ::
 Void -> Void` and `id :: Type -> Type`:

 https://ghc.haskell.org/trac/ghc/ticket/11311?replyto=3#comment:3

 {{{#!hs
 {-# LANGUAGE TypeSynonymInstances, FlexibleInstances #-

 import Data.Kind (Type)

 instance Show Type where
   show _ = "..."

 main = print (undefined :: Type)
 }}}

 running gives:

 {{{
 $ runghc --version
 runghc 8.1.20160113
 $ runghc -ignore-dot-ghci Segfault.hs
 Segmentation fault (core dumped)
 }}}

 Verbose log attached.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11442#comment:2>
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