[GHC] #13132: Compilation fails with a panic: get_op runContT

[GHC]

#13132: Compilation fails with a panic: get_op runContT
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        Reporter:  PoroCYon          |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by adamgundry):

 Thanks for tracking this down. It looks like `get_op` is missing a case
 for `HsRecFld`. The unambiguous case is easy, something like:

 {{{#!hs
 get_op (L _ (HsRecFld (Unambiguous _ n))) = n
 }}}

 That should fix the bug when `DuplicateRecordFields` is disabled, at
 least.

 Unfortunately the case for `Ambiguous` (which may arise when when
 `DuplicateRecordFields` is enabled) is harder, because we don't know which
 `Name` is meant. I'll try to take a look at this, but it may not be very
 soon.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13132#comment:5>
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