[MacPorts] #60853: port mysql8 @8.0.21 fails to build on less than macOS 10.12 due to system libc++ being too old

[MacPorts]

#60853: port mysql8 @8.0.21 fails to build on less than macOS 10.12 due to system
libc++ being too old
----------------------------+-------------------------
  Reporter:  wadjei         |      Owner:  herbygillot
      Type:  defect         |     Status:  assigned
  Priority:  Normal         |  Milestone:
 Component:  ports          |    Version:  2.6.2
Resolution:                 |   Keywords:  mavericks
      Port:  mysql8 libcxx  |
----------------------------+-------------------------

Comment (by kencu):

 I have enabled libcxx-11 in the current installation of clang-11 (it just
 fits there better).

 It is brand new. I don't think anyone has used it for anything yet.

 There are possible issues with using a newer libc++.dylib on older MacOS
 versions -- the issue is called an "ODR violation" if you would like to
 google it and read up on it.

 libc++ and libc++abi are currently installed in the lib directory of
 llvm-11, and tucked away with an @rpath link in them.

 So - go nuts, boys. Kick the tires. See what works, what doesn't work, how
 we might (or might not) be able to use this to solve our troubles.

 Expect problems, and be prepared to come up with solutions too...

-- 
Ticket URL: <https://trac.macports.org/ticket/60853#comment:18>
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