[MacPorts] #60348: libcxx fails to install on Leopard

[MacPorts]

#60348: libcxx fails to install on Leopard
---------------------------+--------------------
  Reporter:  DominusExult  |      Owner:  (none)
      Type:  defect        |     Status:  new
  Priority:  Normal        |  Milestone:
 Component:  ports         |    Version:  2.6.2
Resolution:                |   Keywords:
      Port:  libcxx        |
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Comment (by kencu):

 OK, a few things, but we'll get you going.

 At present, libc++ , clang, llvm, etc only work on Intel systems. I'm
 working on PPC with some other interested parties, but for now, you can't
 use PPC with the llvm infrastructure. So you need to set your "universal
 arches" in ${prefix}/etc/macports/macports.conf to "i386 x86_64" for this
 to work.

 Then you have to follow the instructions step-by-step in
 LibcxxOnOlderSystems, as this process is not automated for MacPorts to do
 this automatically. Basically, you use the system tools to build newer
 cctools and ld64, then build clang-3.4. Then you set your setup to use
 libcxx as per the instructions, and build clang-3.7. Then you use
 clang-3.7 to build clang-5.0 or greater. And finally, you use clang-5.0 or
 greater to rebuild libcxx with the +emulated_tls variant, and you are in
 business.

 MacPorts is not currently set up properly to use Leopard configured with
 libc++ using the default base options, so you need to override these
 default base options by setting you compiler list manually in
 macports.conf, as per the instructions.

 I use Leopard / libc++ all the time, and in fact, I highly recommend it. I
 also have set things up to use Tiger Intel with libc++ as well, and that
 seems to be pretty solid as well, so far --- I have not yet pushed that to
 the main MacPorts repo.

 If the LibcxxOnOlderSystems instructions don't work for you, if they are
 not clear enough, or if there is some other issue you come across that
 seems less-than-clear when following those instructions, please ask and
 I'll see if I can help clarify them further.

-- 
Ticket URL: <https://trac.macports.org/ticket/60348#comment:1>
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