[MacPorts] #42725: Use modern tools for 'port pkg' on newer OS versions

[MacPorts]

#42725: Use modern tools for 'port pkg' on newer OS versions
--------------------------+--------------------------------
  Reporter:  rob@…        |      Owner:  macports-tickets@…
      Type:  enhancement  |     Status:  new
  Priority:  Normal       |  Milestone:
 Component:  base         |    Version:  2.2.1
Resolution:               |   Keywords:
      Port:               |
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Comment (by antonbachin@…):

 Fixing this would be very helpful. I am building packages inside Travis
 build workers, which don't seem to have PackageMaker installed. They do
 have pkgbuild and productbuild.

 I suppose I can ask Travis developers to install PackageMaker in OS X
 images, but it seems like the right place to fix this is MacPorts.

 I'm not aware of any legitimate way to separately install PackageMaker
 without logging in as a developer from the build workers, so this is a
 showstopper for that process.

 Travis build environment summary: https://docs.travis-ci.com/user/osx-ci-
 environment/#OS-X-Version

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Ticket URL: <https://trac.macports.org/ticket/42725#comment:13>
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