[GHC] #11153: building lens-4.12.3 impossible happened: dupe _hs_primitive_memcpy

[GHC]

#11153: building lens-4.12.3 impossible happened: dupe _hs_primitive_memcpy
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        Reporter:  blippy             |                Owner:
            Type:  bug                |               Status:  infoneeded
        Priority:  normal             |            Milestone:
       Component:  libraries (other)  |              Version:  7.10.2
      Resolution:                     |             Keywords:
Operating System:  Windows            |         Architecture:  x86
 Type of failure:  None/Unknown       |            Test Case:
      Blocked By:                     |             Blocking:
 Related Tickets:                     |  Differential Rev(s):
       Wiki Page:                     |
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Comment (by Phyx-):

 Is this still the case with `GHC 8.0.1`? Could you output the trace from
 that? The duplicate error message has been improved to show where both
 symbols come from. That should help diagnose this.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11153#comment:4>
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