[MacPorts] #54289: libcxx{,-abi} : upgrade + "runtime" variant

[MacPorts]

#54289: libcxx{,-abi} : upgrade + "runtime" variant
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  Reporter:  RJVB              |      Owner:  jeremyhu
      Type:  update            |     Status:  assigned
  Priority:  Normal            |  Milestone:
 Component:  ports             |    Version:
Resolution:                    |   Keywords:  haspatch
      Port:  libcxxabi libcxx  |
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Comment (by RJVB):

 Could you please move this to a dedicated ticket?

 Also, if the target intel machine is 32bit as I suspect, I'd advise
 strongly to ignore the instructions to do universal builds. You won't ever
 be able to use the 64bit slices on that machine, so why waste time
 building them (knowing that it must already be very slow to current
 standards).

 I'd also try with clang 3.5, new enough to build libcxx 5 but not so new
 it might give build problems. Alternatively, try GCC like Ken suggested.

 Interesting question: is libc++ built with GCC and itself depending on
 libstdc++ (instead of libc++abi, as on Linux) a viable candidate for the
 libc++ conversion?

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Ticket URL: <https://trac.macports.org/ticket/54289#comment:8>
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