Fixed sync on OS X v10.6 (Snow Leopard).

build/mac/find_sdk.py

Index: build/mac/find_sdk.py
diff --git a/build/mac/find_sdk.py b/build/mac/find_sdk.py
index 1d7634391fa4d66b2baeec276429836c39d53283..30cb57153f902f6e7eb177867d2cffc45a5ae104 100755
--- a/build/mac/find_sdk.py
+++ b/build/mac/find_sdk.py
@@ -77,8 +77,16 @@ def main():
     return min_sdk_version
 
   if options.print_sdk_path:
-    print subprocess.check_output(['xcodebuild', '-version', '-sdk',
-                                   'macosx' + best_sdk, 'Path']).strip()
+    job = subprocess.Popen(['xcodebuild', '-version', '-sdk',
+                            'macosx' + best_sdk, 'Path'],
+                           stdout=subprocess.PIPE,
+                           stderr=subprocess.STDOUT)
+    out, err = job.communicate()
+    if job.returncode != 0:
+      print >>sys.stderr, out
+      print >>sys.stderr, err
+      raise Exception('No %s SDK found' % best_sdk)
+    print out.strip()
 
   return best_sdk