[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
-----------------------+----------------------------
  Reporter:  SaintBol  |      Owner:  (none)
      Type:  defect    |     Status:  new
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:
Resolution:            |   Keywords:  sequoia sonoma
      Port:            |
-----------------------+----------------------------

Comment (by ldionne):

 Hi, I work on the C++ Standard Library and I am currently investigating
 this issue. The workaround that was mentioned by many people (clean
 reinstall of the CLTs) should definitely fix this issue, and so would
 removing all the contents of
 `/Library/Developer/CommandLineTools/usr/include/c++`. The issue seems to
 be that stale headers were present in that directory, leading Clang to
 think that the C++ Standard Library headers to use were in that directory.
 However, the canonical location for C++ Standard Library headers nowadays
 (and for a few years) has been inside the SDK
 (`/Library/Developer/CommandLineTools/SDKs/MacOSX14.5.sdk/usr/include/c++/v1`).

 It would be really helpful if someone who can reproduce the problem
 locally could share the contents of their
 `/Library/Developer/CommandLineTools/usr/include/c++` directory. It seems
 like not everyone has the same content and I have been unable to reproduce
 this issue when installing the CLTs from a clean install, making it a bit
 challenging to investigate.

-- 
Ticket URL: <https://trac.macports.org/ticket/70750#comment:60>
MacPorts <https://www.macports.org/>
Ports system for macOS