[GHC] #9693: Reloading GHCi with Template Haskell names can panic GHC

[GHC]

#9693: Reloading GHCi with Template Haskell names can panic GHC
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        Reporter:  maxs              |                Owner:
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:
       Component:  Template Haskell  |              Version:  7.8.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by thomie):

 * priority:  normal => high


Comment:

 Still reproducible with HEAD. The first error (that you should ignore) is
 now:
 {{{
 thbug.hs:4:1: error:
     Same exact name in multiple name-spaces:
       type constructor or class ‘X’, declared at: thbug.hs:4:1
       data constructor ‘X’, declared at: thbug.hs:4:1
       Probable cause: you bound a unique Template Haskell name (NameU),
       perhaps via newName, in different name-spaces.
       If that's it, then -ddump-splices might be useful
 }}}

 And the panic:
 {{{
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.11.20151213 for x86_64-unknown-linux):
         kcLookupKind APromotionErr RecDataConPE
 }}}

 Panics are bad, raising priority.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9693#comment:3>
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