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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"_osx_support._default_sysroot is dead in CPython but used downstream with no public replacement","articleBody":"`_osx_support._default_sysroot(cc)` has no caller inside CPython, yet several downstream projects import it directly and there is no public replacement to send them to.\n\n## Lifecycle\n\n- GH-23301 (bpo-41116) added it to locate the macOS 11 SDK sysroot when building extensions.\n- Its only in-tree caller lived in `distutils`. GH-99061 (gh-92584) removed `distutils`, so nothing in CPython calls it now.\n\n## Downstream use\n\nA GitHub code search finds live callers: pyston (`setup.py`), PyOxidizer (vendored `distutils/unixccompiler.py`), and the macports and fink Python patches. They call it to discover the SDK sysroot when compiling extensions.\n\n## No public replacement\n\n`sysconfig` does not expose the SDK sysroot and `distutils` is gone, so a downstream user has nowhere supported to move. They would shell out to `xcrun --show-sdk-path` or copy the function body.\n\n## Question\n\nFor this private helper with live downstream use and no public equivalent, which way do we go:\n\n1. Keep it as-is and document that it is unsupported.\n2. Add a supported public equivalent first, then deprecate and remove.\n3. Remove it now under the \"private API carries no guarantee\" rule and accept the breakage.\n","author":{"url":"https://github.com/gaborbernat","@type":"Person","name":"gaborbernat"},"datePublished":"2026-06-03T19:39:58.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/150881/cpython/issues/150881"}