[MacPorts] #64558: libomp @13.0.0_1 fails to build on 10.6

[MacPorts]

#64558: libomp @13.0.0_1 fails to build on 10.6
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  Reporter:  jmroot  |      Owner:  eborisch
      Type:  defect  |     Status:  assigned
  Priority:  Normal  |  Milestone:
 Component:  ports   |    Version:
Resolution:          |   Keywords:  snowleopard
      Port:  libomp  |
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Comment (by kencu):

 there is at present no way to get thread_local_storage on 10.6 without
 manual intervention.

 I floated the simplest fix, just downloading a prebuilt libcxx that has
 thread_local enabled, then building clang-5.0 against that, but that was
 -- let's say disallowed.

 The next simplest fix is ...  more complicated. I had worked out a method
 to build gcc7 from scratch, isolated from MacPorts, use that to bootstrap
 a clang-5.0 built by gcc7 linked against that gcc7's libstdc++, and use
 that as a fully capable compiler to build libc++ (with thread local
 support) and newer clangs.

 But then I tossed that -- life is just too short sometimes.

-- 
Ticket URL: <https://trac.macports.org/ticket/64558#comment:3>
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