[GHC] #13604: ghci no longer loads dynamic .o files by default if they were built with -O

[GHC]

#13604: ghci no longer loads dynamic .o files by default if they were built with -O
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        Reporter:  George            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.4.1
       Component:  GHCi              |              Version:  8.2.1-rc1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3514
       Wiki Page:                    |
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Comment (by elaforge):

 I just ran into this issue myself.  The main thing I have to add is to
 note that this issue also affects -fhpc, so whatever solution should take
 that into account too.  I took a look through FlagChecker.hs for other
 candidates, but didn't see anything else.

 A simple fix would be for ghci to note that -fhpc or -O are being ignored,
 but still include them in its flag hash when it does the recompilation
 check.  I didn't notice that suggestion in the discussion above.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13604#comment:18>
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