[GHC] #7361: Segmentation fault on 5f37e0c71ff4af8539c5aebc739b006b4f0c6ebf

[GHC]

#7361: Segmentation fault on 5f37e0c71ff4af8539c5aebc739b006b4f0c6ebf
---------------------------------+------------------------------------------
    Reporter:  bgamari           |       Owner:  simonmar        
        Type:  bug               |      Status:  new             
    Priority:  highest           |   Milestone:  7.8.1           
   Component:  Compiler          |     Version:  7.7             
    Keywords:                    |          Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |     Failure:  Runtime crash   
  Difficulty:  Unknown           |    Testcase:                  
   Blockedby:                    |    Blocking:                  
     Related:                    |  
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Comment(by simonmar):

 I reproduced this today, but didn't get very far with diagnosing it
 because the code that fails is very complicated.  Something is writing
 beyond the end of an `ARR_WORDS`, and the code blob that does it is in
 `random-source:Data.Random.Source.MWC.$wa`, but that function is huge and
 I have no idea what it is supposed to do.  The error could well be
 somewhere else.  We could add some bounds checks to the array primitives
 (maybe with `-debug`), though I think it probably wouldn't help me in this
 case.

 I have some other bugs I'm chasing so hopefully this one will get fixed as
 a side-effect of fixing something else.  Failing that, we will need a
 smaller test case.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7361#comment:7>
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