diff --git a/tests/fixtures/config/disk-accountant/git/common-config/playbooks/dd-big-empty-file.yaml b/tests/fixtures/config/disk-accountant/git/common-config/playbooks/dd-big-empty-file.yaml
index 95ab870..ba35eb0 100644
--- a/tests/fixtures/config/disk-accountant/git/common-config/playbooks/dd-big-empty-file.yaml
+++ b/tests/fixtures/config/disk-accountant/git/common-config/playbooks/dd-big-empty-file.yaml
@@ -1,6 +1,7 @@
 - hosts: localhost
   tasks:
     - command: dd if=/dev/zero of=toobig bs=1M count=2
+    - command: sync
     - wait_for:
         delay: 10
         path: /
diff --git a/tests/unit/test_disk_accountant.py b/tests/unit/test_disk_accountant.py
index 7081b53..e12846d 100644
--- a/tests/unit/test_disk_accountant.py
+++ b/tests/unit/test_disk_accountant.py
@@ -10,6 +10,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import fixtures
 import os
 import tempfile
 import time
@@ -32,6 +33,10 @@
 
 
 class TestDiskAccountant(BaseTestCase):
+    def setUp(self):
+        super(TestDiskAccountant, self).setUp()
+        self.useFixture(fixtures.NestedTempfile())
+
     def test_disk_accountant(self):
         jobs_dir = tempfile.mkdtemp(
             dir=os.environ.get("ZUUL_TEST_ROOT", None))
@@ -47,6 +52,8 @@
             testfile = os.path.join(jobdir, 'tfile')
             with open(testfile, 'w') as tf:
                 tf.write(2 * 1024 * 1024 * '.')
+                tf.flush()
+                os.fsync(tf.fileno())
 
             # da should catch over-limit dir within 5 seconds
             for i in range(0, 50):
diff --git a/tests/unit/test_encryption.py b/tests/unit/test_encryption.py
index b424769..0a5c0a4 100644
--- a/tests/unit/test_encryption.py
+++ b/tests/unit/test_encryption.py
@@ -12,6 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import fixtures
 import os
 import subprocess
 import tempfile
@@ -26,6 +27,10 @@
     def setUp(self):
         super(TestEncryption, self).setUp()
         self.private, self.public = encryption.generate_rsa_keypair()
+        # Because we set delete to False when using NamedTemporaryFile below
+        # we need to stick our usage of temporary files in the NestedTempfile
+        # fixture ensuring everything gets cleaned up when it is done.
+        self.useFixture(fixtures.NestedTempfile())
 
     def test_serialization(self):
         "Verify key serialization"
diff --git a/tools/github-debugging.py b/tools/github-debugging.py
index 101fd11..da6fd0c 100755
--- a/tools/github-debugging.py
+++ b/tools/github-debugging.py
@@ -11,6 +11,8 @@
 # TODO: for real use override the following variables
 server = 'github.com'
 api_token = 'xxxx'
+appid = 2
+appkey = '/opt/project/appkey'
 
 org = 'example'
 repo = 'sandbox'
@@ -42,20 +44,36 @@
     return conn
 
 
+def create_connection_app(server, appid, appkey):
+    driver = GithubDriver()
+    connection_config = {
+        'server': server,
+        'app_id': appid,
+        'app_key': appkey,
+    }
+    conn = GithubConnection(driver, 'github', connection_config)
+    conn._authenticateGithubAPI()
+    conn._prime_installation_map()
+    return conn
+
+
 def get_change(connection: GithubConnection,
                org: str,
                repo: str,
                pull: int) -> Change:
     p = Project("%s/%s" % (org, repo), connection.source)
-    github = connection.getGithubClient(p)
+    github = connection.getGithubClient(p.name)
     pr = github.pull_request(org, repo, pull)
     sha = pr.head.sha
     return conn._getChange(p, pull, sha, True)
 
 
-# create github connection
+# create github connection with api token
 conn = create_connection(server, api_token)
 
+# create github connection with app key
+# conn = create_connection_app(server, appid, appkey)
+
 
 # Now we can do anything we want with the connection, e.g. check canMerge for
 # a pull request.
diff --git a/tools/nodepool-integration-setup.sh b/tools/nodepool-integration-setup.sh
index c02a016..58c39cf 100755
--- a/tools/nodepool-integration-setup.sh
+++ b/tools/nodepool-integration-setup.sh
@@ -3,7 +3,7 @@
 /usr/zuul-env/bin/zuul-cloner --workspace /tmp --cache-dir /opt/git \
     git://git.openstack.org openstack-infra/nodepool
 
-ln -s /tmp/nodepool/log $WORKSPACE/logs
+ln -s /tmp/nodepool/log $HOME/logs
 
 cd /tmp/openstack-infra/nodepool
 /usr/local/jenkins/slave_scripts/install-distro-packages.sh
diff --git a/zuul/driver/github/githubconnection.py b/zuul/driver/github/githubconnection.py
index 6072f4c..27d31b4 100644
--- a/zuul/driver/github/githubconnection.py
+++ b/zuul/driver/github/githubconnection.py
@@ -458,6 +458,7 @@
         self._github = None
         self.app_id = None
         self.app_key = None
+        self.sched = None
 
         self.installation_map = {}
         self.installation_token_cache = {}
@@ -827,7 +828,8 @@
         change.updated_at = self._ghTimestampToDate(
             change.pr.get('updated_at'))
 
-        self.sched.onChangeUpdated(change)
+        if self.sched:
+            self.sched.onChangeUpdated(change)
 
         return change