Fail compiling from source on macOS 15 with standalone Python. clang++: warning: no such sysroot directory: '/applications/xcode_15.2.app/contents/developer/platforms/macosx.platform/developer/sdks/macosx14.2.sdk'

[ymd-h]

This is a known issue affecting limited users.
Majority of the users are irrelevant.

Affected users

• Building from source
• on macOS 15+, and
• with standalone Python (through uv etc)

Error

clang++: warning: no such sysroot directory: '/applications/xcode_15.2.app/contents/developer/platforms/macosx.platform/developer/sdks/macosx14.2.sdk'

Details

As far as I understand, Python embeds compiler chain information during its installation process,
and use it for compiling extension modules (aka. C/C++ modules) through sysconfig standard library.

Standalone Python is portable and handy 3rd party unofficial binary distribution,
and (maybe) widely used through development tools like uv.
It is quite useful, however, it seems to have difficulty for handling the sysconfig,
since it is compiled beforehand.
astral-sh/python-build-standalone#337
https://gregoryszorc.com/docs/python-build-standalone/main/quirks.html#references-to-build-time-paths

And recently released macOS 15 upgraded Xcode and its SDK path,
so that we fail compiling extension module.