SF patch 1631942 by Collin Winter:
(a) "except E, V" -> "except E as V"
(b) V is now limited to a simple name (local variable)
(c) V is now deleted at the end of the except block
diff --git a/Tools/scripts/ndiff.py b/Tools/scripts/ndiff.py
index 88712b8..2afc132 100755
--- a/Tools/scripts/ndiff.py
+++ b/Tools/scripts/ndiff.py
@@ -61,7 +61,7 @@
 def fopen(fname):
     try:
         return open(fname, 'U')
-    except IOError, detail:
+    except IOError as detail:
         return fail("couldn't open " + fname + ": " + str(detail))
 
 # open two files & spray the diff to stdout; return false iff a problem
@@ -85,7 +85,7 @@
     import getopt
     try:
         opts, args = getopt.getopt(args, "qr:")
-    except getopt.error, detail:
+    except getopt.error as detail:
         return fail(str(detail))
     noisy = 1
     qseen = rseen = 0