[GHC] #12788: While using Data.Aeson.TH, "Irrefutable pattern failed for pattern sel_id : _"

[GHC]

#12788: While using Data.Aeson.TH, "Irrefutable pattern failed for pattern sel_id :
_"
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        Reporter:  jchia             |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by RyanGlScott):

 Ah! It turns out the error I experienced was with versions of GHC 8.0.2
 and HEAD built on October 10. I experienced the same errors as you
 reported when using:

 * A GHC 8.0.2 built on October 18
 * A GHC HEAD built on October 23

 So this GHC panic must have been fixed recently. I'll try to find the
 offending commit.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12788#comment:5>
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