[MacPorts] #70750: C++ headers are not found after updating to CLTs version 16.0

[MacPorts]

#70750: C++ headers are not found after updating to CLTs version 16.0
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  Reporter:  SaintBol  |      Owner:  (none)
      Type:  defect    |     Status:  new
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:
Resolution:            |   Keywords:  sequoia sonoma
      Port:            |
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Comment (by kencu):

 There can (and will) be a number of other issues that come up with various
 other ports. But as far as we can tell the c++ compiler in the CLTs does
 work with a clean installation of the CLTs from the DMG, whereas it does
 not work with an upgraded installation of the CLTs.

 If you just delete the CLTs and build everything using Xcode, then some
 things will be hard coded against the SDKs in Xcode. This will work for a
 while, or maybe not, as all of MacPorts has been set up to use the SDKs in
 {{{/Library/Developer/CommandLineTools/SDKS}}} and base and Portfiles are
 not written to use Xcode.

 After you do the fixes here to make the CLTs work, if you find issues with
 certain ports that don't build, just post up tickets (or add to existing
 tickets) and things will be sorted out.

-- 
Ticket URL: <https://trac.macports.org/ticket/70750#comment:55>
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