[GHC] #13695: Highly nested UNPACKed data causes panic

[GHC]

#13695: Highly nested UNPACKed data causes panic
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        Reporter:  ryanreich     |                Owner:  (none)
            Type:  bug           |               Status:  new
        Priority:  high          |            Milestone:  8.2.1
       Component:  Compiler      |              Version:  8.2.1-rc2
      Resolution:                |             Keywords:
Operating System:  Linux         |         Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown  |            Test Case:
      Blocked By:                |             Blocking:
 Related Tickets:  #3990         |  Differential Rev(s):
       Wiki Page:                |
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Comment (by ryanreich):

 I'm using exactly the same builds myself.  I went and tried it with HEAD
 and it seemed to have the same failure, but after switching the version
 back and forth a few times it started actually working (!).  I was doing
 `stack clean` in between, so the runs should have been independent.  I
 can't make it happen at all anymore, so I wonder if it was an issue of the
 dynamic libraries with the same version having been mapped into memory,
 and now replaced with the correct one?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13695#comment:5>
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