[MacPorts] #63084: py37-pyobjc fails to build

[MacPorts]

#63084: py37-pyobjc fails to build
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  Reporter:  tonywong94  |      Owner:  danchr
      Type:  defect      |     Status:  assigned
  Priority:  Normal      |  Milestone:
 Component:  ports       |    Version:  2.7.1
Resolution:              |   Keywords:
      Port:  py-pyobjc   |
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Comment (by danchr):

 Sigh… So, the issue was that previously, PyObjC would build with the
 system headers for libffi, and link against MacPort's libffi. Through
 mostly happenstance, I'd say, that worked. That changed with Big Sur,
 which added some symbols — for arm64 — that Apple has yet to fully
 contribute upstream.

 I can think of a few ways to fix this:

 1. Go back to previous way of including things on anything but Big Sur,
 even if it's conceptually broken.
 1. Always use the system libffi, and hope that it fixes things. PyObjC is
 much more likely to actually test and fix bugs with system libraries than
 whatever we provide.
 1. Just fix this particular error, which is caused by a deprecation
 warning, and remove `-Werror` from the build.
 1. If possible, fix the deprecation warning and contribute it upstream.

 Personally, I'd rather not do the first option, even if it seems tempting.
 My inclination is to use the third or fourth option: Properly fix PyObjC
 to work with MacPorts' libffi, however possible, but do keep using it.
 With correct includes and all.

 I'm not entirely certain which way is best; perhaps some of you could
 provide some feedback?

-- 
Ticket URL: <https://trac.macports.org/ticket/63084#comment:3>
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