[MacPorts] #59837: macOS 10.14 SDK does not appear to be installed even though Command Line Tools are installed

[MacPorts]

#59837: macOS 10.14 SDK does not appear to be installed even though Command Line
Tools are installed
------------------------+--------------------
  Reporter:  manulcaux  |      Owner:  (none)
      Type:  defect     |     Status:  new
  Priority:  Normal     |  Milestone:
 Component:  base       |    Version:
Resolution:             |   Keywords:
      Port:             |
------------------------+--------------------

Comment (by RiotNrrrd):

 ''So why am I getting the warning?''

 [''**Updating my own comment.**'']

 I found this Web page:

 [https://donatstudios.com/MojaveMissingHeaderFiles]

 which says to run

 {{{
 $ sudo installer -pkg
 /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg
 -target /
 }}}

 This worked, and I was able to install ports like ''mercurial'' that
 previously errored on 10.14.6 due to missing header files.

 But I'm still getting the

 {{{
 Warning: The macOS 10.14 SDK does not appear to be installed. Ports may
 not build correctly.
 Warning: You can install it as part of the Xcode Command Line Tools
 package by running `xcode-select --install'.
 }}}

 warnings on this system, even after having done that.

 I think it's because I have Xcode 11.3.1 on this system, and it installed
 a Catalina SDK in the Xcode tree instead of a Mojave one.

 (Even though the SDK installed by the Command Line Tools installer is
 still the version for Mojave.)

 {{{
 mymac:~ root# locate /MacOSX10.1
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk
 /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk
 }}}

 On another Mojave development system where I have the older Xcode 10.3
 version installed, I do ''not'' get the

 {{{
 Warning: The macOS 10.14 SDK does not appear to be installed. Ports may
 not build correctly.
 Warning: You can install it as part of the Xcode Command Line Tools
 package by running `xcode-select --install'.
 }}}

 warnings.  I believe this is because both SDKs located under the Xcode and
 Command Line Tools trees are for Mojave:

 {{{
 devmac:~ root# locate /MacOSX10.1
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk
 /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk
 }}}

 Hoping this helps someone if they run into the same situation.

-- 
Ticket URL: <https://trac.macports.org/ticket/59837#comment:20>
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