Re: [GHC] #13615: Nondeterminism in ‘pure’ function w/ parallel evaluation & memo combinators

[GHC]

#13615: Nondeterminism in ‘pure’ function w/ parallel evaluation & memo combinators
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        Reporter:  pacak             |                Owner:  bgamari
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by bgamari):

 One interesting observation is that the issue persists even if the list
 passed to `fromListWith` is fully forced; that is,
 {{{#!hs
     let xs' = deepseq xs `seq` HM.toList (HM.fromListWith (+) xs)
 }}}
 instead of
 {{{#!hs
     let xs' = HM.toList (HM.fromListWith (+) xs)
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13615#comment:35>
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