diff --git a/.zuul.yaml b/.zuul.yaml
index 84bb45c2f858c4e54d39cadce50ede7e7390c34e..4066fb485dcffe5fa00d43fb7bf0120e30f09d3c 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -2,7 +2,7 @@
     templates:
       - check-requirements
       - lib-forward-testing-python3
-      - openstack-python3-xena-jobs
+      - openstack-python3-yoga-jobs
       - periodic-stable-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3
diff --git a/oslo_service/_options.py b/oslo_service/_options.py
index 0b356d217221c1dae416b0849230e0f235435bb6..72c06f36cb733972f31a7264ec3888a3140acbf2 100644
--- a/oslo_service/_options.py
+++ b/oslo_service/_options.py
@@ -88,6 +88,11 @@ wsgi_opts = [
                     "If an incoming connection is idle for this number of "
                     "seconds it will be closed. A value of '0' means "
                     "wait forever."),
+    cfg.BoolOpt('wsgi_server_debug',
+                default=False,
+                help="True if the server should send exception tracebacks to "
+                     "the clients on 500 errors. If False, the server will "
+                     "respond with empty bodies."),
     ]
 
 ssl_opts = [
diff --git a/oslo_service/eventlet_backdoor.py b/oslo_service/eventlet_backdoor.py
index 83908055ff96b77ca01483f3da8f00188b4b0750..ada9a938ca8de3308879abe540ccc0eb4e37ef9f 100644
--- a/oslo_service/eventlet_backdoor.py
+++ b/oslo_service/eventlet_backdoor.py
@@ -86,7 +86,8 @@ def _detailed_dump_frames(f, thread_index):
 
 
 def _find_objects(t):
-    return [o for o in gc.get_objects() if isinstance(o, t)]
+    return [o for o in gc.get_objects()
+            if hasattr(o, "__class__") and isinstance(o, t)]
 
 
 def _capture_profile(fname=''):
diff --git a/oslo_service/loopingcall.py b/oslo_service/loopingcall.py
index 32c7573a78fe254bdf2014685f1b5f1d68aa672a..794f0cfd6bdab69ad952230748b3de93ee1fc656 100644
--- a/oslo_service/loopingcall.py
+++ b/oslo_service/loopingcall.py
@@ -348,7 +348,7 @@ class BackOffLoopingCall(LoopingCallBase):
                 if timeout > 0 and self._error_time + idle > timeout:
                     raise LoopingCallTimeOut(
                         _('Looping call timed out after %.02f seconds')
-                        % self._error_time)
+                        % (self._error_time + idle))
                 self._error_time += idle
                 return idle
 
diff --git a/oslo_service/wsgi.py b/oslo_service/wsgi.py
index 731e2a468b4edd7b0e3664934d74de300ba8de29..8b518bd295f61528092413eb2b1a1767d4de6491 100644
--- a/oslo_service/wsgi.py
+++ b/oslo_service/wsgi.py
@@ -180,7 +180,7 @@ class Server(service.ServiceBase):
             'custom_pool': self._pool,
             'log': self._logger,
             'log_format': self.conf.wsgi_log_format,
-            'debug': False,
+            'debug': self.conf.wsgi_server_debug,
             'keepalive': self.conf.wsgi_keep_alive,
             'socket_timeout': self.client_socket_timeout
             }
diff --git a/releasenotes/notes/add-wsgi_server_debug-opt-70d818b5b78bfc7c.yaml b/releasenotes/notes/add-wsgi_server_debug-opt-70d818b5b78bfc7c.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..b9a952cdb838d2fd207cb22e6a0c0f14a949eaa5
--- /dev/null
+++ b/releasenotes/notes/add-wsgi_server_debug-opt-70d818b5b78bfc7c.yaml
@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    A new config options, ``[DEFAULT] wsgi_server_debug``, has been added.
+    This allows admins to configure whether the server should send exception
+    tracebacks to the clients on HTTP 500 errors. This defaults to ``False``,
+    preserving previous behavior.
diff --git a/releasenotes/notes/fix-find-object-in-backdoor-487bf78c4c502594.yaml b/releasenotes/notes/fix-find-object-in-backdoor-487bf78c4c502594.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..31c088ade5ac14b1d15060e7ee1b04bd943bd706
--- /dev/null
+++ b/releasenotes/notes/fix-find-object-in-backdoor-487bf78c4c502594.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fix the backdoor helper method fo() to also work when there are objects
+    present in the current python instance that do not have a __class__
+    attribute.
diff --git a/releasenotes/source/index.rst b/releasenotes/source/index.rst
index 0d4a4e69077ffaa50d74c0cf4c79c4901a3b10b1..ae4e6d8986296fbe0a47ec079b7fd621b7166535 100644
--- a/releasenotes/source/index.rst
+++ b/releasenotes/source/index.rst
@@ -6,6 +6,7 @@
    :maxdepth: 1
 
    unreleased
+   xena
    wallaby
    victoria
    ussuri
diff --git a/releasenotes/source/xena.rst b/releasenotes/source/xena.rst
new file mode 100644
index 0000000000000000000000000000000000000000..1be85be3ebf18741d311aa41096d417a99c970bf
--- /dev/null
+++ b/releasenotes/source/xena.rst
@@ -0,0 +1,6 @@
+=========================
+Xena Series Release Notes
+=========================
+
+.. release-notes::
+   :branch: stable/xena