[GHC] #8862: forkProcess does not play well with heap or time profiling

[GHC]

#8862: forkProcess does not play well with heap or time profiling
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       Reporter:          |             Owner:  simonmar
  bennofs                 |            Status:  new
           Type:  bug     |         Milestone:
       Priority:  normal  |           Version:  7.6.3
      Component:          |  Operating System:  Unknown/Multiple
  Runtime System          |   Type of failure:  Incorrect result at runtime
       Keywords:          |         Test Case:
   Architecture:          |          Blocking:
  Unknown/Multiple        |
     Difficulty:          |
  Unknown                 |
     Blocked By:          |
Related Tickets:          |
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 This is similar to #4512. When doing heap or time profiling, the forked
 process and the parent process both write to the same `.hp` or `.prof`
 file. I think this also applies to program coverage using hpc (didn't test
 this).

 I was able to reproduce the bug with the attached source code, but some
 other people were not. Just run `space-profiling +RTS -h` and try to
 convert the generated heap profile using `hp2ps`, I get the following
 error message:

 {{{
 hp2ps: space-profiling.hp, line 186: integer must follow identifier
 }}}

 I attached the generated hp file.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8862>
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