[GHC] #11681: ghc panic with TypeError

[GHC]

#11681: ghc panic with TypeError
-------------------------------------+-------------------------------------
        Reporter:  inaki             |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.0.1
       Component:  Compiler (Type    |              Version:  8.0.1-rc2
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash                              |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by bgamari):

 * failure:  None/Unknown => Compile-time crash
 * version:  7.10.3 => 8.0.1-rc2
 * component:  Compiler => Compiler (Type checker)
 * milestone:   => 8.0.1


Comment:

 What GHC version were you attempting to compile with? I don't believe it
 could have been 7.10.3 given that `TypeError` was only introduced in
 8.0.1.

 Unfortunately, I'm having trouble reproducing this with any of the 8.0.1
 release candidates. In all cases I get,
 {{{#!hs
 $ ghc Test.hs
 [1 of 1] Compiling Main             ( Test.hs, Test.o )

 Test.hs:8:42: error:
     • Expected kind ‘ErrorMessage’, but ‘"B"’ has kind ‘Symbol’
     • In the second argument of ‘:<>:’, namely ‘"B"’
       In the first argument of ‘TypeError’, namely ‘Text "A" :<>: "B"’
       In the instance declaration for ‘C t’
 }}}
 which appears to be the correct error.

 There have been a number of similar tickets which have been recently
 closed (e.g. #11563) with,
 [changeset:"b565830dda0994d5d67617039db3310f81e831c8/ghc" b565830d/ghc].

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11681#comment:1>
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