Half of the fix for issue 6957: ensure that distutils
ignores the '-isysroot' option on OSX when the
corresponding SDK is not installed.
This ensures that the user can compile extensions
on OSX 10.6 using the Python.org installer and a
default installation of Xcode.
diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
index dcc7231..6ca6720 100644
--- a/Lib/distutils/sysconfig.py
+++ b/Lib/distutils/sysconfig.py
@@ -592,6 +592,29 @@
flags = flags + ' ' + arch
_config_vars[key] = flags
+ # If we're on OSX 10.5 or later and the user tries to
+ # compiles an extension using an SDK that is not present
+ # on the current machine it is better to not use an SDK
+ # than to fail.
+ #
+ # The major usecase for this is users using a Python.org
+ # binary installer on OSX 10.6: that installer uses
+ # the 10.4u SDK, but that SDK is not installed by default
+ # when you install Xcode.
+ #
+ m = re.search('-isysroot\s+(\S+)', _config_vars['CFLAGS'])
+ if m is not None:
+ sdk = m.group(1)
+ if not os.path.exists(sdk):
+ for key in ('LDFLAGS', 'BASECFLAGS',
+ # a number of derived variables. These need to be
+ # patched up as well.
+ 'CFLAGS', 'PY_CFLAGS', 'BLDSHARED'):
+
+ flags = _config_vars[key]
+ flags = re.sub('-isysroot\s+\S+(\s|$)', ' ', flags)
+ _config_vars[key] = flags
+
if args:
vals = []
for name in args: