[GHC] #15892: Segmentation fault with ByteString and -O

[GHC]

#15892: Segmentation fault with ByteString and -O
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           Reporter:  akio            |             Owner:  (none)
               Type:  bug             |            Status:  new
           Priority:  normal          |         Milestone:  8.6.3
          Component:  Compiler        |           Version:  8.6.2
           Keywords:                  |  Operating System:  Linux
       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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 The attached program consistently segfaults (within a few seconds) when
 compiled with ghc-8.6.1 or ghc-8.6.2. It runs forever (as expected) when
 compiled with ghc-8.4.

 To reproduce:

 {{{
 ghc segfault.hs
 }}}

 then,

 {{{
 ./segfault >/dev/null
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15892>
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