[GHC] #15608: Segfault in retainer profiling

[GHC]

#15608: Segfault in retainer profiling
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           Reporter:  osa1           |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:  8.6.1
          Component:  Profiling      |           Version:  8.5
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 To reproduce, build ghc using "prof" flavor, then

 {{{
 $ ghc-stage2 --interactive +RTS -hr
 GHCi, version 8.7.20180905: http://www.haskell.org/ghc/  :? for help
 Loaded GHCi configuration from /home/omer/rcbackup/.ghci
 λ:1> sequence_ (replicate 100000000 (return ()))
 zsh: segmentation fault (core dumped)  ghc-stage2 --interactive +RTS -hr
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15608>
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