[GHC] #15891: Excessive system time during execution of GHC-built executables on macOS

[GHC]

#15891: Excessive system time during execution of GHC-built executables on macOS
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        Reporter:  goldfire      |                Owner:  (none)
            Type:  bug           |               Status:  new
        Priority:  normal        |            Milestone:  8.6.3
       Component:  Compiler      |              Version:  8.6.2
      Resolution:                |             Keywords:
Operating System:  MacOS X       |         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 goldfire):

 I should add a few details, inspired by comment:4

 - My BuildFlavour = devel2
 - Used `make -j5`

 I needed to `chmod u+s` `dtruss` to get it to work... but then, later, had
 trouble and so had to revert this change. Just posting here to avoid
 @gridaphobe problems later.

 To sample, I ran `sample ghc-stage1` while GHC was compiling in another
 terminal session.

 Glad to know I'm not alone here!

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15891#comment:5>
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