emit a message when falling-back to xcrun dyldinfo

Author: kavon

utils/swift-darwin-postprocess.py

@@ -39,6 +39,7 @@ def unrpathize(filename):
             ['xcrun', 'dyld_info', '-dependents', filename],
             universal_newlines=True)
     except subprocess.CalledProcessError:
+        sys.stderr.write("falling back to 'xcrun dyldinfo' ...\n")
         dylibsOutput = subprocess.check_output(
             ['xcrun', 'dyldinfo', '-dylibs', filename],
             universal_newlines=True)

utils/swift-rpathize.py

@@ -63,6 +63,7 @@ def rpathize(filename):
             ['xcrun', 'dyld_info', '-dependents', filename],
             universal_newlines=True)
     except subprocess.CalledProcessError:
+        sys.stderr.write("falling back to 'xcrun dyldinfo' ...\n")
         dylibsOutput = subprocess.check_output(
             ['xcrun', 'dyldinfo', '-dylibs', filename],
             universal_newlines=True)