[GHC] #15671: Link errors due to forcibly exporting findPtr

[GHC]

#15671: Link errors due to forcibly exporting findPtr
-------------------------------------+-------------------------------------
           Reporter:  Phyx-          |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:  8.6.1
          Component:  Compiler       |           Version:  8.4.3
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:  T10955dyn      |        Blocked By:
  T10955                             |
           Blocking:                 |   Related Tickets:
Differential Rev(s):  Phab:D5138     |         Wiki Page:
-------------------------------------+-------------------------------------
 The change in
 https://phabricator.haskell.org/rGHC900c47f88784b91517c00be3e1087322e62f698e
 is causing link errors due to the combination of `-Wl,-u` and `-Wl
 ,--export-all-symbols`

 {{{
 Wrong exit code for T10955dyn()(expected 0 , actual 2 )
 Stderr ( T10955dyn ):
 E:/ghc-
 dev/msys64/home/Tamar/ghc/rts/dist/build/libHSrts_thr.a(Printer.thr_o): In
 function `findPtr':
 E:\ghc-dev\msys64\home\Tamar\ghc/rts/Printer.c:880: multiple definition of
 `findPtr'
 ./bin_dyn/libA.dll.a(d020776.o):(.text+0x0): first defined here
 }}}

 I believe the correct solution is to just use a cabal flag to emulate the
 setup we had with make, instead of forcing this symbol always.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15671>
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