bpo-41129: Fix check for macOS SDK paths when building Python (GH-25785) (GH-25830)

Narrow search to match contents of SDKs, namely only files in ``/System/Library``,
``/System/IOSSupport``, and ``/usr`` other than ``/usr/local``. Previously,
anything under ``/System`` was assumed to be in an SDK which causes problems
with the new file system layout in 10.15+ where user file systems may appear
to be mounted under ``/System``.  Paths in ``/Library`` were also
incorrectly treated as SDK locations.

Co-authored-by: Ned Deily <nad@python.org>
(cherry picked from commit d52bbde9421987d216c600557ef5bc931d03efcc)

Co-authored-by: Ned Batchelder <ned@nedbatchelder.com>

diff --git a/Misc/NEWS.d/next/macOS/2021-05-02-21-03-27.bpo-42119.Y7BSX_.rst b/Misc/NEWS.d/next/macOS/2021-05-02-21-03-27.bpo-42119.Y7BSX_.rst
new file mode 100644 (file)
index 0000000..7dd67a5
--- /dev/null
+++ b/Misc/NEWS.d/next/macOS/2021-05-02-21-03-27.bpo-42119.Y7BSX_.rst
@@ -0,0 +1,7 @@
+Fix check for macOS SDK paths when building Python. Narrow search to match
+contents of SDKs, namely only files in ``/System/Library``,
+``/System/IOSSupport``, and ``/usr`` other than ``/usr/local``. Previously,
+anything under ``/System`` was assumed to be in an SDK which causes problems
+with the new file system layout in 10.15+ where user file systems may appear
+to be mounted under ``/System``.  Paths in ``/Library`` were also
+incorrectly treated as SDK locations.

diff --git a/setup.py b/setup.py
index d8941790b35d00361e635bf471f3e1a775ab82a6..04eb6b291c770560ab0c18a97539348738ca624b 100644 (file)
--- a/setup.py
+++ b/setup.py
@@ -210,11 +210,11 @@ def macosx_sdk_specified():
 
 def is_macosx_sdk_path(path):
     """
-    Returns True if 'path' can be located in an OSX SDK
+    Returns True if 'path' can be located in a macOS SDK
     """
     return ( (path.startswith('/usr/') and not path.startswith('/usr/local'))
-                or path.startswith('/System/')
-                or path.startswith('/Library/') )
+                or path.startswith('/System/Library')
+                or path.startswith('/System/iOSSupport') )
 
 
 def grep_headers_for(function, headers):