bpo-41116: Ensure system supplied libraries are found on macOS 11 (GH-23301)
On macOS system provided libraries are in a shared library cache
and not at their usual location. This PR teaches distutils to search
in the SDK, even if there was no "-sysroot" argument in
the compiler flags.
diff --git a/Lib/distutils/unixccompiler.py b/Lib/distutils/unixccompiler.py
index 4d7a6de..f0792de 100644
--- a/Lib/distutils/unixccompiler.py
+++ b/Lib/distutils/unixccompiler.py
@@ -290,7 +290,7 @@ def find_library_file(self, dirs, lib, debug=0):
cflags = sysconfig.get_config_var('CFLAGS')
m = re.search(r'-isysroot\s*(\S+)', cflags)
if m is None:
- sysroot = '/'
+ sysroot = _osx_support._default_sysroot(sysconfig.get_config_var('CC'))
else:
sysroot = m.group(1)