[MacPorts] #70750: MacOS Sequoia: C++ headers are not found with CLTs installed

[MacPorts]

#70750: MacOS Sequoia: C++ headers are not found with CLTs installed
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  Reporter:  SaintBol  |      Owner:  (none)
      Type:  defect    |     Status:  new
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:
Resolution:            |   Keywords:  sequoia
      Port:            |
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Comment (by wdormann):

 Replying to [comment:42 jmroot]:
 > It turns out the problematic leftover is the
 `/Library/Developer/CommandLineTools/usr/include/c++` directory, which
 doesn't exist in a working installation, and when deleted from a broken
 one makes it work.

 Courtesy of a Time Machine backup, I can confirm that in my case, this was
 also the case.
 `/Library/Developer/CommandLineTools/usr/include/c++` was present:
 {{{
 $ find c++/
 c++/
 c++/v1
 c++/v1/experimental
 c++/v1/experimental/any
 c++/v1/experimental/chrono
 c++/v1/experimental/numeric
 c++/v1/experimental/optional
 c++/v1/experimental/ratio
 c++/v1/experimental/string_view
 c++/v1/experimental/system_error
 c++/v1/experimental/tuple
 c++/v1/__cxx_version
 c++/v1/__functional_03
 c++/v1/__functional_base_03
 c++/v1/__sso_allocator
 }}}

 Not a lot there, but presumably its mere presence (without the relevant
 includes that some things are looking for) is enough to confuse the build
 process for some packages.

 Aside from fixing this MacPorts problem, deleting that directory also
 cleared up about 1.5GB of disk space as well, as the old directory also
 had SDK directories for MacOSX 10.14, 10.15, 11.1, and 12.1.

-- 
Ticket URL: <https://trac.macports.org/ticket/70750#comment:44>
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