[GHC] #4820: "Invalid object in isRetainer" when doing retainer profiling in GHC 7 branch

[GHC]

#4820: "Invalid object in isRetainer" when doing retainer profiling in GHC 7
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        Reporter:  dleuschner     |                Owner:
            Type:  bug            |               Status:  new
        Priority:  high           |            Milestone:  8.0.2
       Component:  Profiling      |              Version:  7.10.3
      Resolution:                 |             Keywords:
Operating System:  MacOS X        |         Architecture:  x86_64 (amd64)
 Type of failure:  Runtime crash  |            Test Case:
      Blocked By:                 |             Blocking:
 Related Tickets:                 |  Differential Rev(s):
       Wiki Page:                 |
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Comment (by carter):

 The code at work that trips this is open source, but I'm not sure how
 reproducible the crash is atm

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4820#comment:7>
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