Missed one because of indirection.
diff --git a/Lib/distutils/util.py b/Lib/distutils/util.py
index e0ae2e5..917f1d0 100644
--- a/Lib/distutils/util.py
+++ b/Lib/distutils/util.py
@@ -269,7 +269,7 @@
             # include the filename in the exception object!
             error = prefix + "%s" % exc.strerror
     else:
-        error = prefix + str(exc[-1])
+        error = prefix + str(exc.args[-1])
 
     return error