fix reraise case for python 3

2 files changed, 4 insertions, 2 deletions

diff --git a/pyramid/compat.py b/pyramid/compat.py
index 3ac235b0f..73f52b617 100644
--- a/pyramid/compat.py
+++ b/pyramid/compat.py
@@ -101,6 +101,8 @@ if PY3: # pragma: no cover
 
 
     def reraise(tp, value, tb=None):
+        if value is None:
+            value = tp
         if value.__traceback__ is not tb:
             raise value.with_traceback(tb)
         raise value
diff --git a/pyramid/mako_templating.py b/pyramid/mako_templating.py
index 9980faf9d..e4571ba1b 100644
--- a/pyramid/mako_templating.py
+++ b/pyramid/mako_templating.py
@@ -8,7 +8,7 @@ from zope.interface import Interface
 from pyramid.asset import resolve_asset_spec
 from pyramid.asset import abspath_from_asset_spec
 from pyramid.compat import is_nonstr_iter
-from pyramid.exceptions import ConfigurationError
+from pyramid.compat import reraise
 from pyramid.interfaces import ITemplateRenderer
 from pyramid.settings import asbool
 from pyramid.util import DottedNameResolver
@@ -151,7 +151,7 @@ class MakoLookupTemplateRenderer(object):
                     error=exc_info[1],
                     traceback=exc_info[2]
                     )
-                raise MakoRenderingException(errtext), None, exc_info[2]
+                reraise(MakoRenderingException(errtext), None, exc_info[2])
             finally:
                 del exc_info