Don't use sys.exc_value

sys.exc_value has been deprecated since Python 1.5, and is not thread-safe.
The replacement is sys.exc_info(), but in this case we don't need even that
since we have the exception in question available.

Change-Id: Ibb4b354fd099fbf0d6390163eb4f7cc9e97db0e9
Signed-off-by: Zane Bitter <zbitter@redhat.com>

heat/engine/manager.py

@@ -20,7 +20,6 @@ import datetime
 import functools
 import os
 import socket
-import sys
 import tempfile
 import time
 import traceback
@@ -210,9 +209,9 @@ class EngineManager(manager.Manager):
 
         try:
             s = parser.Stack(context, 'validate', template, 0, params)
-        except KeyError:
-            res = 'A Fn::FindInMap operation referenced'\
-                  'a non-existent map [%s]' % sys.exc_value
+        except KeyError as ex:
+            res = ('A Fn::FindInMap operation referenced '
+                   'a non-existent map [%s]' % str(ex))
 
             response = {'ValidateTemplateResult': {
                         'Description': 'Malformed Query Response [%s]' % (res),

heat/engine/parser.py

@@ -16,7 +16,6 @@
 import eventlet
 import json
 import logging
-import sys
 from heat.common import exception
 from heat.engine import checkeddict
 from heat.engine import cloud_watch
@@ -112,9 +111,9 @@ class Stack(object):
         response = None
         try:
             order = self.get_create_order()
-        except KeyError:
+        except KeyError as ex:
             res = 'A Ref operation referenced a non-existent key '\
-                  '[%s]' % sys.exc_value
+                  '[%s]' % str(ex)
 
             response = {'ValidateTemplateResult': {
                         'Description': 'Malformed Query Response [%s]' % (res),