[GHC] #14097: -ddump-json doesn't interact as expected with -ddump-to-file

[GHC]

#14097: -ddump-json doesn't interact as expected with -ddump-to-file
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        Reporter:  mpickering        |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:  JSON
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by mpickering):

 There is quiet a fundamental problem that even if we propagate this
 information outwards, functions like `parUpsweep_one` operate in IO, on an
 exception this means that the updated dflags are not set and the output it
 still printed on stdout.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14097#comment:2>
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