diff --git a/doc/source/reporters.rst b/doc/source/reporters.rst
index e3ab947..dd053fa 100644
--- a/doc/source/reporters.rst
+++ b/doc/source/reporters.rst
@@ -44,6 +44,10 @@
   set as the commit status on github.
   ``status: 'success'``
 
+  **status-url**
+  String value for a link url to set in the github status. Defaults to the zuul
+  server status_url, or the empty string if that is unset.
+
   **comment**
   Boolean value (``true`` or ``false``) that determines if the reporter should
   add a comment to the pipeline status to the github pull request. Defaults
diff --git a/tests/base.py b/tests/base.py
index c6f1a4b..48716e2 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -1221,6 +1221,25 @@
         self.log.debug("  OK")
         return True
 
+    def getWorkspaceRepos(self, projects):
+        """Return workspace git repo objects for the listed projects
+
+        :arg list projects: A list of strings, each the canonical name
+                            of a project.
+
+        :returns: A dictionary of {name: repo} for every listed
+                  project.
+        :rtype: dict
+
+        """
+
+        repos = {}
+        for project in projects:
+            path = os.path.join(self.jobdir.src_root, project)
+            repo = git.Repo(path)
+            repos[project] = repo
+        return repos
+
 
 class RecordingExecutorServer(zuul.executor.server.ExecutorServer):
     """An Ansible executor to be used in tests.
@@ -1307,10 +1326,10 @@
 
 
 class RecordingAnsibleJob(zuul.executor.server.AnsibleJob):
-    def doMergeChanges(self, items, repo_state):
+    def doMergeChanges(self, merger, items, repo_state):
         # Get a merger in order to update the repos involved in this job.
         commit = super(RecordingAnsibleJob, self).doMergeChanges(
-            items, repo_state)
+            merger, items, repo_state)
         if not commit:  # merge conflict
             self.recordResult('MERGER_FAILURE')
         return commit
@@ -2190,6 +2209,8 @@
 
     def shutdown(self):
         self.log.debug("Shutting down after tests")
+        self.executor_server.hold_jobs_in_build = False
+        self.executor_server.release()
         self.executor_client.stop()
         self.merge_client.stop()
         self.executor_server.stop()
@@ -2675,6 +2696,29 @@
                 specified_conn.server == conn.server):
                 conn.addEvent(event)
 
+    def getUpstreamRepos(self, projects):
+        """Return upstream git repo objects for the listed projects
+
+        :arg list projects: A list of strings, each the canonical name
+                            of a project.
+
+        :returns: A dictionary of {name: repo} for every listed
+                  project.
+        :rtype: dict
+
+        """
+
+        repos = {}
+        for project in projects:
+            # FIXME(jeblair): the upstream root does not yet have a
+            # hostname component; that needs to be added, and this
+            # line removed:
+            tmp_project_name = '/'.join(project.split('/')[1:])
+            path = os.path.join(self.upstream_root, tmp_project_name)
+            repo = git.Repo(path)
+            repos[project] = repo
+        return repos
+
 
 class AnsibleZuulTestCase(ZuulTestCase):
     """ZuulTestCase but with an actual ansible executor running"""
diff --git a/tests/fixtures/layouts/repo-checkout-four-project.yaml b/tests/fixtures/layouts/repo-checkout-four-project.yaml
new file mode 100644
index 0000000..392931a
--- /dev/null
+++ b/tests/fixtures/layouts/repo-checkout-four-project.yaml
@@ -0,0 +1,81 @@
+- pipeline:
+    name: check
+    manager: independent
+    trigger:
+      gerrit:
+        - event: patchset-created
+    success:
+      gerrit:
+        verified: 1
+    failure:
+      gerrit:
+        verified: -1
+
+- pipeline:
+    name: gate
+    manager: dependent
+    success-message: Build succeeded (gate).
+    trigger:
+      gerrit:
+        - event: comment-added
+          approval:
+            - approved: 1
+    success:
+      gerrit:
+        verified: 2
+        submit: true
+    failure:
+      gerrit:
+        verified: -2
+    start:
+      gerrit:
+        verified: 0
+    precedence: high
+
+- job:
+    name: integration
+    required-projects:
+      - org/project1
+      - org/project2
+      - org/project3
+      - org/project4
+
+- project:
+    name: org/project1
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
+
+- project:
+    name: org/project2
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
+
+- project:
+    name: org/project3
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
+
+- project:
+    name: org/project4
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
diff --git a/tests/fixtures/layouts/repo-checkout-no-timer.yaml b/tests/fixtures/layouts/repo-checkout-no-timer.yaml
new file mode 100644
index 0000000..2b65850
--- /dev/null
+++ b/tests/fixtures/layouts/repo-checkout-no-timer.yaml
@@ -0,0 +1,20 @@
+- pipeline:
+    name: periodic
+    manager: independent
+    # Trigger is required, set it to one that is a noop
+    # during tests that check the timer trigger.
+    trigger:
+      gerrit:
+        - event: ref-updated
+
+- job:
+    name: integration
+    override-branch: stable/havana
+    required-projects:
+      - org/project1
+
+- project:
+    name: org/project1
+    periodic:
+      jobs:
+        - integration
diff --git a/tests/fixtures/layouts/repo-checkout-post.yaml b/tests/fixtures/layouts/repo-checkout-post.yaml
new file mode 100644
index 0000000..9698289
--- /dev/null
+++ b/tests/fixtures/layouts/repo-checkout-post.yaml
@@ -0,0 +1,25 @@
+- pipeline:
+    name: post
+    manager: independent
+    trigger:
+      gerrit:
+        - event: ref-updated
+          ref: ^(?!refs/).*$
+
+- job:
+    name: integration
+    required-projects:
+      - org/project1
+      - org/project2
+
+- project:
+    name: org/project1
+    post:
+      jobs:
+        - integration
+
+- project:
+    name: org/project2
+    post:
+      jobs:
+        - integration
diff --git a/tests/fixtures/layouts/repo-checkout-six-project.yaml b/tests/fixtures/layouts/repo-checkout-six-project.yaml
new file mode 100644
index 0000000..93a64ea
--- /dev/null
+++ b/tests/fixtures/layouts/repo-checkout-six-project.yaml
@@ -0,0 +1,104 @@
+- pipeline:
+    name: check
+    manager: independent
+    trigger:
+      gerrit:
+        - event: patchset-created
+    success:
+      gerrit:
+        verified: 1
+    failure:
+      gerrit:
+        verified: -1
+
+- pipeline:
+    name: gate
+    manager: dependent
+    success-message: Build succeeded (gate).
+    trigger:
+      gerrit:
+        - event: comment-added
+          approval:
+            - approved: 1
+    success:
+      gerrit:
+        verified: 2
+        submit: true
+    failure:
+      gerrit:
+        verified: -2
+    start:
+      gerrit:
+        verified: 0
+    precedence: high
+
+- job:
+    name: integration
+    required-projects:
+      - org/project1
+      - org/project2
+      - org/project3
+      - name: org/project4
+        override-branch: master
+      - org/project5
+      - org/project6
+
+- project:
+    name: org/project1
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
+
+- project:
+    name: org/project2
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
+
+- project:
+    name: org/project3
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
+
+- project:
+    name: org/project4
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
+
+- project:
+    name: org/project5
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
+
+- project:
+    name: org/project6
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
diff --git a/tests/fixtures/layouts/repo-checkout-timer.yaml b/tests/fixtures/layouts/repo-checkout-timer.yaml
new file mode 100644
index 0000000..d5917d1
--- /dev/null
+++ b/tests/fixtures/layouts/repo-checkout-timer.yaml
@@ -0,0 +1,18 @@
+- pipeline:
+    name: periodic
+    manager: independent
+    trigger:
+      timer:
+        - time: '* * * * * */1'
+
+- job:
+    name: integration
+    override-branch: stable/havana
+    required-projects:
+      - org/project1
+
+- project:
+    name: org/project1
+    periodic:
+      jobs:
+        - integration
diff --git a/tests/fixtures/layouts/repo-checkout-two-project.yaml b/tests/fixtures/layouts/repo-checkout-two-project.yaml
new file mode 100644
index 0000000..239d80c
--- /dev/null
+++ b/tests/fixtures/layouts/repo-checkout-two-project.yaml
@@ -0,0 +1,59 @@
+- pipeline:
+    name: check
+    manager: independent
+    trigger:
+      gerrit:
+        - event: patchset-created
+    success:
+      gerrit:
+        verified: 1
+    failure:
+      gerrit:
+        verified: -1
+
+- pipeline:
+    name: gate
+    manager: dependent
+    success-message: Build succeeded (gate).
+    trigger:
+      gerrit:
+        - event: comment-added
+          approval:
+            - approved: 1
+    success:
+      gerrit:
+        verified: 2
+        submit: true
+    failure:
+      gerrit:
+        verified: -2
+    start:
+      gerrit:
+        verified: 0
+    precedence: high
+
+- job:
+    name: integration
+    required-projects:
+      - org/project1
+      - org/project2
+
+- project:
+    name: org/project1
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
+
+- project:
+    name: org/project2
+    check:
+      jobs:
+        - integration
+    gate:
+      queue: integrated
+      jobs:
+        - integration
diff --git a/tests/fixtures/layouts/reporting-github.yaml b/tests/fixtures/layouts/reporting-github.yaml
index c939f39..8dd35b0 100644
--- a/tests/fixtures/layouts/reporting-github.yaml
+++ b/tests/fixtures/layouts/reporting-github.yaml
@@ -29,6 +29,7 @@
       github:
         comment: false
         status: 'success'
+        status-url: http://logs.example.com/{pipeline.name}/{change.project}/{change.number}/{change.patchset}/
     failure:
       github:
         comment: false
diff --git a/tests/fixtures/zuul-github-driver.conf b/tests/fixtures/zuul-github-driver.conf
index ab34619..dfa813d 100644
--- a/tests/fixtures/zuul-github-driver.conf
+++ b/tests/fixtures/zuul-github-driver.conf
@@ -3,7 +3,7 @@
 
 [zuul]
 job_name_in_report=true
-status_url=http://zuul.example.com/status
+status_url=http://zuul.example.com/status/#{change.number},{change.patchset}
 
 [merger]
 git_dir=/tmp/zuul-test/git
diff --git a/tests/unit/test_cloner.py b/tests/unit/test_cloner.py
deleted file mode 100644
index e65904b..0000000
--- a/tests/unit/test_cloner.py
+++ /dev/null
@@ -1,752 +0,0 @@
-#!/usr/bin/env python
-
-# Copyright 2012 Hewlett-Packard Development Company, L.P.
-# Copyright 2014 Wikimedia Foundation Inc.
-#
-# Licensed under the Apache License, Version 2.0 (the "License"); you may
-# not use this file except in compliance with the License. You may obtain
-# a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations
-# under the License.
-
-import logging
-import os
-import shutil
-import time
-
-import git
-
-import zuul.lib.cloner
-
-from tests.base import ZuulTestCase
-
-
-class TestCloner(ZuulTestCase):
-
-    log = logging.getLogger("zuul.test.cloner")
-    workspace_root = None
-
-    def setUp(self):
-        self.skip("Disabled for early v3 development")
-
-        super(TestCloner, self).setUp()
-        self.workspace_root = os.path.join(self.test_root, 'workspace')
-
-        self.updateConfigLayout(
-            'tests/fixtures/layout-cloner.yaml')
-        self.sched.reconfigure(self.config)
-        self.registerJobs()
-
-    def getWorkspaceRepos(self, projects):
-        repos = {}
-        for project in projects:
-            repos[project] = git.Repo(
-                os.path.join(self.workspace_root, project))
-        return repos
-
-    def getUpstreamRepos(self, projects):
-        repos = {}
-        for project in projects:
-            repos[project] = git.Repo(
-                os.path.join(self.upstream_root, project))
-        return repos
-
-    def test_cache_dir(self):
-        projects = ['org/project1', 'org/project2']
-        cache_root = os.path.join(self.test_root, "cache")
-        for project in projects:
-            upstream_repo_path = os.path.join(self.upstream_root, project)
-            cache_repo_path = os.path.join(cache_root, project)
-            git.Repo.clone_from(upstream_repo_path, cache_repo_path)
-
-        self.worker.hold_jobs_in_build = True
-        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
-        A.addApproval('CRVW', 2)
-        self.fake_gerrit.addEvent(A.addApproval('APRV', 1))
-
-        self.waitUntilSettled()
-
-        self.assertEquals(1, len(self.builds), "One build is running")
-
-        B = self.fake_gerrit.addFakeChange('org/project2', 'master', 'B')
-        B.setMerged()
-
-        upstream = self.getUpstreamRepos(projects)
-        states = [{
-            'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-            'org/project2': str(upstream['org/project2'].commit('master')),
-        }]
-
-        for number, build in enumerate(self.builds):
-            self.log.debug("Build parameters: %s", build.parameters)
-            cloner = zuul.lib.cloner.Cloner(
-                git_base_url=self.upstream_root,
-                projects=projects,
-                workspace=self.workspace_root,
-                zuul_project=build.parameters.get('ZUUL_PROJECT', None),
-                zuul_branch=build.parameters['ZUUL_BRANCH'],
-                zuul_ref=build.parameters['ZUUL_REF'],
-                zuul_url=self.src_root,
-                cache_dir=cache_root,
-            )
-            cloner.execute()
-            work = self.getWorkspaceRepos(projects)
-            state = states[number]
-
-            for project in projects:
-                self.assertEquals(state[project],
-                                  str(work[project].commit('HEAD')),
-                                  'Project %s commit for build %s should '
-                                  'be correct' % (project, number))
-
-        work = self.getWorkspaceRepos(projects)
-        # project1 is the zuul_project so the origin should be set to the
-        # zuul_url since that is the most up to date.
-        cache_repo_path = os.path.join(cache_root, 'org/project1')
-        self.assertNotEqual(
-            work['org/project1'].remotes.origin.url,
-            cache_repo_path,
-            'workspace repo origin should not be the cache'
-        )
-        zuul_url_repo_path = os.path.join(self.git_root, 'org/project1')
-        self.assertEqual(
-            work['org/project1'].remotes.origin.url,
-            zuul_url_repo_path,
-            'workspace repo origin should be the zuul url'
-        )
-
-        # project2 is not the zuul_project so the origin should be set
-        # to upstream since that is the best we can do
-        cache_repo_path = os.path.join(cache_root, 'org/project2')
-        self.assertNotEqual(
-            work['org/project2'].remotes.origin.url,
-            cache_repo_path,
-            'workspace repo origin should not be the cache'
-        )
-        upstream_repo_path = os.path.join(self.upstream_root, 'org/project2')
-        self.assertEqual(
-            work['org/project2'].remotes.origin.url,
-            upstream_repo_path,
-            'workspace repo origin should be the upstream url'
-        )
-
-        self.worker.hold_jobs_in_build = False
-        self.worker.release()
-        self.waitUntilSettled()
-
-    def test_one_branch(self):
-        self.worker.hold_jobs_in_build = True
-
-        projects = ['org/project1', 'org/project2']
-        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
-        B = self.fake_gerrit.addFakeChange('org/project2', 'master', 'B')
-        A.addApproval('CRVW', 2)
-        B.addApproval('CRVW', 2)
-        self.fake_gerrit.addEvent(A.addApproval('APRV', 1))
-        self.fake_gerrit.addEvent(B.addApproval('APRV', 1))
-
-        self.waitUntilSettled()
-
-        self.assertEquals(2, len(self.builds), "Two builds are running")
-
-        upstream = self.getUpstreamRepos(projects)
-        states = [
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit('master')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': self.builds[1].parameters['ZUUL_COMMIT'],
-             },
-        ]
-
-        for number, build in enumerate(self.builds):
-            self.log.debug("Build parameters: %s", build.parameters)
-            cloner = zuul.lib.cloner.Cloner(
-                git_base_url=self.upstream_root,
-                projects=projects,
-                workspace=self.workspace_root,
-                zuul_project=build.parameters.get('ZUUL_PROJECT', None),
-                zuul_branch=build.parameters['ZUUL_BRANCH'],
-                zuul_ref=build.parameters['ZUUL_REF'],
-                zuul_url=self.src_root,
-            )
-            cloner.execute()
-            work = self.getWorkspaceRepos(projects)
-            state = states[number]
-
-            for project in projects:
-                self.assertEquals(state[project],
-                                  str(work[project].commit('HEAD')),
-                                  'Project %s commit for build %s should '
-                                  'be correct' % (project, number))
-
-            shutil.rmtree(self.workspace_root)
-
-        self.worker.hold_jobs_in_build = False
-        self.worker.release()
-        self.waitUntilSettled()
-
-    def test_multi_branch(self):
-        self.worker.hold_jobs_in_build = True
-        projects = ['org/project1', 'org/project2',
-                    'org/project3', 'org/project4']
-
-        self.create_branch('org/project2', 'stable/havana')
-        self.create_branch('org/project4', 'stable/havana')
-        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
-        B = self.fake_gerrit.addFakeChange('org/project2', 'stable/havana',
-                                           'B')
-        C = self.fake_gerrit.addFakeChange('org/project3', 'master', 'C')
-        A.addApproval('CRVW', 2)
-        B.addApproval('CRVW', 2)
-        C.addApproval('CRVW', 2)
-        self.fake_gerrit.addEvent(A.addApproval('APRV', 1))
-        self.fake_gerrit.addEvent(B.addApproval('APRV', 1))
-        self.fake_gerrit.addEvent(C.addApproval('APRV', 1))
-
-        self.waitUntilSettled()
-
-        self.assertEquals(3, len(self.builds), "Three builds are running")
-
-        upstream = self.getUpstreamRepos(projects)
-        states = [
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit('master')),
-             'org/project3': str(upstream['org/project3'].commit('master')),
-             'org/project4': str(upstream['org/project4'].
-                                 commit('master')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': self.builds[1].parameters['ZUUL_COMMIT'],
-             'org/project3': str(upstream['org/project3'].commit('master')),
-             'org/project4': str(upstream['org/project4'].
-                                 commit('stable/havana')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit('master')),
-             'org/project3': self.builds[2].parameters['ZUUL_COMMIT'],
-             'org/project4': str(upstream['org/project4'].
-                                 commit('master')),
-             },
-        ]
-
-        for number, build in enumerate(self.builds):
-            self.log.debug("Build parameters: %s", build.parameters)
-            cloner = zuul.lib.cloner.Cloner(
-                git_base_url=self.upstream_root,
-                projects=projects,
-                workspace=self.workspace_root,
-                zuul_project=build.parameters.get('ZUUL_PROJECT', None),
-                zuul_branch=build.parameters['ZUUL_BRANCH'],
-                zuul_ref=build.parameters['ZUUL_REF'],
-                zuul_url=self.src_root,
-            )
-            cloner.execute()
-            work = self.getWorkspaceRepos(projects)
-            state = states[number]
-
-            for project in projects:
-                self.assertEquals(state[project],
-                                  str(work[project].commit('HEAD')),
-                                  'Project %s commit for build %s should '
-                                  'be correct' % (project, number))
-            shutil.rmtree(self.workspace_root)
-
-        self.worker.hold_jobs_in_build = False
-        self.worker.release()
-        self.waitUntilSettled()
-
-    def test_upgrade(self):
-        # Simulates an upgrade test
-        self.worker.hold_jobs_in_build = True
-        projects = ['org/project1', 'org/project2', 'org/project3',
-                    'org/project4', 'org/project5', 'org/project6']
-
-        self.create_branch('org/project2', 'stable/havana')
-        self.create_branch('org/project3', 'stable/havana')
-        self.create_branch('org/project4', 'stable/havana')
-        self.create_branch('org/project5', 'stable/havana')
-        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
-        B = self.fake_gerrit.addFakeChange('org/project2', 'master', 'B')
-        C = self.fake_gerrit.addFakeChange('org/project3', 'stable/havana',
-                                           'C')
-        D = self.fake_gerrit.addFakeChange('org/project3', 'master', 'D')
-        E = self.fake_gerrit.addFakeChange('org/project4', 'stable/havana',
-                                           'E')
-        A.addApproval('CRVW', 2)
-        B.addApproval('CRVW', 2)
-        C.addApproval('CRVW', 2)
-        D.addApproval('CRVW', 2)
-        E.addApproval('CRVW', 2)
-        self.fake_gerrit.addEvent(A.addApproval('APRV', 1))
-        self.fake_gerrit.addEvent(B.addApproval('APRV', 1))
-        self.fake_gerrit.addEvent(C.addApproval('APRV', 1))
-        self.fake_gerrit.addEvent(D.addApproval('APRV', 1))
-        self.fake_gerrit.addEvent(E.addApproval('APRV', 1))
-
-        self.waitUntilSettled()
-
-        self.assertEquals(5, len(self.builds), "Five builds are running")
-
-        # Check the old side of the upgrade first
-        upstream = self.getUpstreamRepos(projects)
-        states = [
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit(
-                                 'stable/havana')),
-             'org/project3': str(upstream['org/project3'].commit(
-                                 'stable/havana')),
-             'org/project4': str(upstream['org/project4'].commit(
-                                 'stable/havana')),
-             'org/project5': str(upstream['org/project5'].commit(
-                                 'stable/havana')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit(
-                                 'stable/havana')),
-             'org/project3': str(upstream['org/project3'].commit(
-                                 'stable/havana')),
-             'org/project4': str(upstream['org/project4'].commit(
-                                 'stable/havana')),
-             'org/project5': str(upstream['org/project5'].commit(
-                                 'stable/havana')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit(
-                                 'stable/havana')),
-             'org/project3': self.builds[2].parameters['ZUUL_COMMIT'],
-             'org/project4': str(upstream['org/project4'].commit(
-                                 'stable/havana')),
-
-             'org/project5': str(upstream['org/project5'].commit(
-                                 'stable/havana')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit(
-                                 'stable/havana')),
-             'org/project3': self.builds[2].parameters['ZUUL_COMMIT'],
-             'org/project4': str(upstream['org/project4'].commit(
-                                 'stable/havana')),
-             'org/project5': str(upstream['org/project5'].commit(
-                                 'stable/havana')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit(
-                                 'stable/havana')),
-             'org/project3': self.builds[2].parameters['ZUUL_COMMIT'],
-             'org/project4': self.builds[4].parameters['ZUUL_COMMIT'],
-             'org/project5': str(upstream['org/project5'].commit(
-                                 'stable/havana')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-        ]
-
-        for number, build in enumerate(self.builds):
-            self.log.debug("Build parameters: %s", build.parameters)
-            cloner = zuul.lib.cloner.Cloner(
-                git_base_url=self.upstream_root,
-                projects=projects,
-                workspace=self.workspace_root,
-                zuul_project=build.parameters.get('ZUUL_PROJECT', None),
-                zuul_branch=build.parameters['ZUUL_BRANCH'],
-                zuul_ref=build.parameters['ZUUL_REF'],
-                zuul_url=self.src_root,
-                branch='stable/havana',  # Old branch for upgrade
-            )
-            cloner.execute()
-            work = self.getWorkspaceRepos(projects)
-            state = states[number]
-
-            for project in projects:
-                self.assertEquals(state[project],
-                                  str(work[project].commit('HEAD')),
-                                  'Project %s commit for build %s should '
-                                  'be correct on old side of upgrade' %
-                                  (project, number))
-            shutil.rmtree(self.workspace_root)
-
-        # Check the new side of the upgrade
-        states = [
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit('master')),
-             'org/project3': str(upstream['org/project3'].commit('master')),
-             'org/project4': str(upstream['org/project4'].commit('master')),
-             'org/project5': str(upstream['org/project5'].commit('master')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': self.builds[1].parameters['ZUUL_COMMIT'],
-             'org/project3': str(upstream['org/project3'].commit('master')),
-             'org/project4': str(upstream['org/project4'].commit('master')),
-             'org/project5': str(upstream['org/project5'].commit('master')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': self.builds[1].parameters['ZUUL_COMMIT'],
-             'org/project3': str(upstream['org/project3'].commit('master')),
-             'org/project4': str(upstream['org/project4'].commit('master')),
-             'org/project5': str(upstream['org/project5'].commit('master')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': self.builds[1].parameters['ZUUL_COMMIT'],
-             'org/project3': self.builds[3].parameters['ZUUL_COMMIT'],
-             'org/project4': str(upstream['org/project4'].commit('master')),
-             'org/project5': str(upstream['org/project5'].commit('master')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': self.builds[1].parameters['ZUUL_COMMIT'],
-             'org/project3': self.builds[3].parameters['ZUUL_COMMIT'],
-             'org/project4': str(upstream['org/project4'].commit('master')),
-             'org/project5': str(upstream['org/project5'].commit('master')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-        ]
-
-        for number, build in enumerate(self.builds):
-            self.log.debug("Build parameters: %s", build.parameters)
-            cloner = zuul.lib.cloner.Cloner(
-                git_base_url=self.upstream_root,
-                projects=projects,
-                workspace=self.workspace_root,
-                zuul_project=build.parameters.get('ZUUL_PROJECT', None),
-                zuul_branch=build.parameters['ZUUL_BRANCH'],
-                zuul_ref=build.parameters['ZUUL_REF'],
-                zuul_url=self.src_root,
-                branch='master',  # New branch for upgrade
-            )
-            cloner.execute()
-            work = self.getWorkspaceRepos(projects)
-            state = states[number]
-
-            for project in projects:
-                self.assertEquals(state[project],
-                                  str(work[project].commit('HEAD')),
-                                  'Project %s commit for build %s should '
-                                  'be correct on old side of upgrade' %
-                                  (project, number))
-            shutil.rmtree(self.workspace_root)
-
-        self.worker.hold_jobs_in_build = False
-        self.worker.release()
-        self.waitUntilSettled()
-
-    def test_project_override(self):
-        self.worker.hold_jobs_in_build = True
-        projects = ['org/project1', 'org/project2', 'org/project3',
-                    'org/project4', 'org/project5', 'org/project6']
-
-        self.create_branch('org/project3', 'stable/havana')
-        self.create_branch('org/project4', 'stable/havana')
-        self.create_branch('org/project6', 'stable/havana')
-        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
-        B = self.fake_gerrit.addFakeChange('org/project1', 'master', 'B')
-        C = self.fake_gerrit.addFakeChange('org/project2', 'master', 'C')
-        D = self.fake_gerrit.addFakeChange('org/project3', 'stable/havana',
-                                           'D')
-        A.addApproval('CRVW', 2)
-        B.addApproval('CRVW', 2)
-        C.addApproval('CRVW', 2)
-        D.addApproval('CRVW', 2)
-        self.fake_gerrit.addEvent(A.addApproval('APRV', 1))
-        self.fake_gerrit.addEvent(B.addApproval('APRV', 1))
-        self.fake_gerrit.addEvent(C.addApproval('APRV', 1))
-        self.fake_gerrit.addEvent(D.addApproval('APRV', 1))
-
-        self.waitUntilSettled()
-
-        self.assertEquals(4, len(self.builds), "Four builds are running")
-
-        upstream = self.getUpstreamRepos(projects)
-        states = [
-            {'org/project1': self.builds[0].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit('master')),
-             'org/project3': str(upstream['org/project3'].commit('master')),
-             'org/project4': str(upstream['org/project4'].commit('master')),
-             'org/project5': str(upstream['org/project5'].commit('master')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[1].parameters['ZUUL_COMMIT'],
-             'org/project2': str(upstream['org/project2'].commit('master')),
-             'org/project3': str(upstream['org/project3'].commit('master')),
-             'org/project4': str(upstream['org/project4'].commit('master')),
-             'org/project5': str(upstream['org/project5'].commit('master')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[1].parameters['ZUUL_COMMIT'],
-             'org/project2': self.builds[2].parameters['ZUUL_COMMIT'],
-             'org/project3': str(upstream['org/project3'].commit('master')),
-             'org/project4': str(upstream['org/project4'].commit('master')),
-             'org/project5': str(upstream['org/project5'].commit('master')),
-             'org/project6': str(upstream['org/project6'].commit('master')),
-             },
-            {'org/project1': self.builds[1].parameters['ZUUL_COMMIT'],
-             'org/project2': self.builds[2].parameters['ZUUL_COMMIT'],
-             'org/project3': self.builds[3].parameters['ZUUL_COMMIT'],
-             'org/project4': str(upstream['org/project4'].commit('master')),
-             'org/project5': str(upstream['org/project5'].commit('master')),
-             'org/project6': str(upstream['org/project6'].commit(
-                                 'stable/havana')),
-             },
-        ]
-
-        for number, build in enumerate(self.builds):
-            self.log.debug("Build parameters: %s", build.parameters)
-            cloner = zuul.lib.cloner.Cloner(
-                git_base_url=self.upstream_root,
-                projects=projects,
-                workspace=self.workspace_root,
-                zuul_project=build.parameters.get('ZUUL_PROJECT', None),
-                zuul_branch=build.parameters['ZUUL_BRANCH'],
-                zuul_ref=build.parameters['ZUUL_REF'],
-                zuul_url=self.src_root,
-                project_branches={'org/project4': 'master'},
-            )
-            cloner.execute()
-            work = self.getWorkspaceRepos(projects)
-            state = states[number]
-
-            for project in projects:
-                self.assertEquals(state[project],
-                                  str(work[project].commit('HEAD')),
-                                  'Project %s commit for build %s should '
-                                  'be correct' % (project, number))
-            shutil.rmtree(self.workspace_root)
-
-        self.worker.hold_jobs_in_build = False
-        self.worker.release()
-        self.waitUntilSettled()
-
-    def test_periodic(self):
-        self.worker.hold_jobs_in_build = True
-        self.create_branch('org/project', 'stable/havana')
-        self.updateConfigLayout(
-            'tests/fixtures/layout-timer.yaml')
-        self.sched.reconfigure(self.config)
-        self.registerJobs()
-
-        # The pipeline triggers every second, so we should have seen
-        # several by now.
-        time.sleep(5)
-        self.waitUntilSettled()
-
-        builds = self.builds[:]
-
-        self.worker.hold_jobs_in_build = False
-        # Stop queuing timer triggered jobs so that the assertions
-        # below don't race against more jobs being queued.
-        self.updateConfigLayout(
-            'tests/fixtures/layout-no-timer.yaml')
-        self.sched.reconfigure(self.config)
-        self.registerJobs()
-        self.worker.release()
-        self.waitUntilSettled()
-
-        projects = ['org/project']
-
-        self.assertEquals(2, len(builds), "Two builds are running")
-
-        upstream = self.getUpstreamRepos(projects)
-        states = [
-            {'org/project':
-                str(upstream['org/project'].commit('stable/havana')),
-             },
-            {'org/project':
-                str(upstream['org/project'].commit('stable/havana')),
-             },
-        ]
-
-        for number, build in enumerate(builds):
-            self.log.debug("Build parameters: %s", build.parameters)
-            cloner = zuul.lib.cloner.Cloner(
-                git_base_url=self.upstream_root,
-                projects=projects,
-                workspace=self.workspace_root,
-                zuul_project=build.parameters.get('ZUUL_PROJECT', None),
-                zuul_branch=build.parameters.get('ZUUL_BRANCH', None),
-                zuul_ref=build.parameters.get('ZUUL_REF', None),
-                zuul_url=self.src_root,
-                branch='stable/havana',
-            )
-            cloner.execute()
-            work = self.getWorkspaceRepos(projects)
-            state = states[number]
-
-            for project in projects:
-                self.assertEquals(state[project],
-                                  str(work[project].commit('HEAD')),
-                                  'Project %s commit for build %s should '
-                                  'be correct' % (project, number))
-
-            shutil.rmtree(self.workspace_root)
-
-        self.worker.hold_jobs_in_build = False
-        self.worker.release()
-        self.waitUntilSettled()
-
-    def test_periodic_update(self):
-        # Test that the merger correctly updates its local repository
-        # before running a periodic job.
-
-        # Prime the merger with the current state
-        A = self.fake_gerrit.addFakeChange('org/project', 'master', 'A')
-        self.fake_gerrit.addEvent(A.getPatchsetCreatedEvent(1))
-        self.waitUntilSettled()
-
-        # Merge a different change
-        B = self.fake_gerrit.addFakeChange('org/project', 'master', 'B')
-        B.setMerged()
-
-        # Start a periodic job
-        self.worker.hold_jobs_in_build = True
-        self.executor.negative_function_cache_ttl = 0
-        self.config.set('zuul', 'layout_config',
-                        'tests/fixtures/layout-timer.yaml')
-        self.sched.reconfigure(self.config)
-        self.registerJobs()
-
-        # The pipeline triggers every second, so we should have seen
-        # several by now.
-        time.sleep(5)
-        self.waitUntilSettled()
-
-        builds = self.builds[:]
-
-        self.worker.hold_jobs_in_build = False
-        # Stop queuing timer triggered jobs so that the assertions
-        # below don't race against more jobs being queued.
-        self.config.set('zuul', 'layout_config',
-                        'tests/fixtures/layout-no-timer.yaml')
-        self.sched.reconfigure(self.config)
-        self.registerJobs()
-        self.worker.release()
-        self.waitUntilSettled()
-
-        projects = ['org/project']
-
-        self.assertEquals(2, len(builds), "Two builds are running")
-
-        upstream = self.getUpstreamRepos(projects)
-        self.assertEqual(upstream['org/project'].commit('master').hexsha,
-                         B.patchsets[0]['revision'])
-        states = [
-            {'org/project':
-                str(upstream['org/project'].commit('master')),
-             },
-            {'org/project':
-                str(upstream['org/project'].commit('master')),
-             },
-        ]
-
-        for number, build in enumerate(builds):
-            self.log.debug("Build parameters: %s", build.parameters)
-            cloner = zuul.lib.cloner.Cloner(
-                git_base_url=self.upstream_root,
-                projects=projects,
-                workspace=self.workspace_root,
-                zuul_project=build.parameters.get('ZUUL_PROJECT', None),
-                zuul_branch=build.parameters.get('ZUUL_BRANCH', None),
-                zuul_ref=build.parameters.get('ZUUL_REF', None),
-                zuul_url=self.git_root,
-            )
-            cloner.execute()
-            work = self.getWorkspaceRepos(projects)
-            state = states[number]
-
-            for project in projects:
-                self.assertEquals(state[project],
-                                  str(work[project].commit('HEAD')),
-                                  'Project %s commit for build %s should '
-                                  'be correct' % (project, number))
-
-            shutil.rmtree(self.workspace_root)
-
-        self.worker.hold_jobs_in_build = False
-        self.worker.release()
-        self.waitUntilSettled()
-
-    def test_post_checkout(self):
-        self.worker.hold_jobs_in_build = True
-        project = "org/project1"
-
-        A = self.fake_gerrit.addFakeChange(project, 'master', 'A')
-        event = A.getRefUpdatedEvent()
-        A.setMerged()
-        self.fake_gerrit.addEvent(event)
-        self.waitUntilSettled()
-
-        build = self.builds[0]
-        state = {'org/project1': build.parameters['ZUUL_COMMIT']}
-
-        build.release()
-        self.waitUntilSettled()
-
-        cloner = zuul.lib.cloner.Cloner(
-            git_base_url=self.upstream_root,
-            projects=[project],
-            workspace=self.workspace_root,
-            zuul_project=build.parameters.get('ZUUL_PROJECT', None),
-            zuul_branch=build.parameters.get('ZUUL_BRANCH', None),
-            zuul_ref=build.parameters.get('ZUUL_REF', None),
-            zuul_newrev=build.parameters.get('ZUUL_NEWREV', None),
-            zuul_url=self.git_root,
-        )
-        cloner.execute()
-        work = self.getWorkspaceRepos([project])
-        self.assertEquals(state[project],
-                          str(work[project].commit('HEAD')),
-                          'Project %s commit for build %s should '
-                          'be correct' % (project, 0))
-        shutil.rmtree(self.workspace_root)
-
-    def test_post_and_master_checkout(self):
-        self.worker.hold_jobs_in_build = True
-        projects = ["org/project1", "org/project2"]
-
-        A = self.fake_gerrit.addFakeChange(projects[0], 'master', 'A')
-        event = A.getRefUpdatedEvent()
-        A.setMerged()
-        self.fake_gerrit.addEvent(event)
-        self.waitUntilSettled()
-
-        build = self.builds[0]
-        upstream = self.getUpstreamRepos(projects)
-        state = {'org/project1':
-                 build.parameters['ZUUL_COMMIT'],
-                 'org/project2':
-                 str(upstream['org/project2'].commit('master')),
-                 }
-
-        build.release()
-        self.waitUntilSettled()
-
-        cloner = zuul.lib.cloner.Cloner(
-            git_base_url=self.upstream_root,
-            projects=projects,
-            workspace=self.workspace_root,
-            zuul_project=build.parameters.get('ZUUL_PROJECT', None),
-            zuul_branch=build.parameters.get('ZUUL_BRANCH', None),
-            zuul_ref=build.parameters.get('ZUUL_REF', None),
-            zuul_newrev=build.parameters.get('ZUUL_NEWREV', None),
-            zuul_url=self.git_root,
-        )
-        cloner.execute()
-        work = self.getWorkspaceRepos(projects)
-
-        for project in projects:
-            self.assertEquals(state[project],
-                              str(work[project].commit('HEAD')),
-                              'Project %s commit for build %s should '
-                              'be correct' % (project, 0))
-        shutil.rmtree(self.workspace_root)
diff --git a/tests/unit/test_cloner_cmd.py b/tests/unit/test_cloner_cmd.py
index 2d8747f..84bd243 100644
--- a/tests/unit/test_cloner_cmd.py
+++ b/tests/unit/test_cloner_cmd.py
@@ -26,7 +26,7 @@
 
     def test_default_cache_dir_empty(self):
         self.app.parse_arguments(['base', 'repo'])
-        self.assertEqual(None, self.app.args.cache_dir)
+        self.assertIsNone(self.app.args.cache_dir)
 
     def test_default_cache_dir_environ(self):
         try:
diff --git a/tests/unit/test_executor.py b/tests/unit/test_executor.py
new file mode 100644
index 0000000..100e4ec
--- /dev/null
+++ b/tests/unit/test_executor.py
@@ -0,0 +1,349 @@
+#!/usr/bin/env python
+
+# Copyright 2012 Hewlett-Packard Development Company, L.P.
+# Copyright 2014 Wikimedia Foundation Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import logging
+import time
+
+from tests.base import ZuulTestCase, simple_layout
+
+
+class TestExecutorRepos(ZuulTestCase):
+    tenant_config_file = 'config/single-tenant/main.yaml'
+
+    log = logging.getLogger("zuul.test.executor")
+
+    def assertRepoState(self, repo, state, project, build, number):
+        if 'branch' in state:
+            self.assertFalse(repo.head.is_detached,
+                             'Project %s commit for build %s #%s should '
+                             'not have a detached HEAD' % (
+                                 project, build, number))
+            self.assertEquals(repo.active_branch.name,
+                              state['branch'],
+                              'Project %s commit for build %s #%s should '
+                              'be on the correct branch' % (
+                                  project, build, number))
+        if 'commit' in state:
+            self.assertEquals(state['commit'],
+                              str(repo.commit('HEAD')),
+                              'Project %s commit for build %s #%s should '
+                              'be correct' % (
+                                  project, build, number))
+        ref = repo.commit('HEAD')
+        repo_messages = set(
+            [c.message.strip() for c in repo.iter_commits(ref)])
+        if 'present' in state:
+            for change in state['present']:
+                msg = '%s-1' % change.subject
+                self.assertTrue(msg in repo_messages,
+                                'Project %s for build %s #%s should '
+                                'have change %s' % (
+                                    project, build, number, change.subject))
+        if 'absent' in state:
+            for change in state['absent']:
+                msg = '%s-1' % change.subject
+                self.assertTrue(msg not in repo_messages,
+                                'Project %s for build %s #%s should '
+                                'not have change %s' % (
+                                    project, build, number, change.subject))
+
+    @simple_layout('layouts/repo-checkout-two-project.yaml')
+    def test_one_branch(self):
+        self.executor_server.hold_jobs_in_build = True
+
+        p1 = 'review.example.com/org/project1'
+        p2 = 'review.example.com/org/project2'
+        projects = [p1, p2]
+        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
+        B = self.fake_gerrit.addFakeChange('org/project2', 'master', 'B')
+        A.addApproval('code-review', 2)
+        B.addApproval('code-review', 2)
+        self.fake_gerrit.addEvent(A.addApproval('approved', 1))
+        self.fake_gerrit.addEvent(B.addApproval('approved', 1))
+
+        self.waitUntilSettled()
+
+        self.assertEquals(2, len(self.builds), "Two builds are running")
+
+        upstream = self.getUpstreamRepos(projects)
+        states = [
+            {p1: dict(present=[A], absent=[B], branch='master'),
+             p2: dict(commit=str(upstream[p2].commit('master')),
+                      branch='master'),
+             },
+            {p1: dict(present=[A], absent=[B], branch='master'),
+             p2: dict(present=[B], absent=[A], branch='master'),
+             },
+        ]
+
+        for number, build in enumerate(self.builds):
+            self.log.debug("Build parameters: %s", build.parameters)
+            work = build.getWorkspaceRepos(projects)
+            state = states[number]
+
+            for project in projects:
+                self.assertRepoState(work[project], state[project],
+                                     project, build, number)
+
+        self.executor_server.hold_jobs_in_build = False
+        self.executor_server.release()
+        self.waitUntilSettled()
+
+    @simple_layout('layouts/repo-checkout-four-project.yaml')
+    def test_multi_branch(self):
+        self.executor_server.hold_jobs_in_build = True
+
+        p1 = 'review.example.com/org/project1'
+        p2 = 'review.example.com/org/project2'
+        p3 = 'review.example.com/org/project3'
+        p4 = 'review.example.com/org/project4'
+        projects = [p1, p2, p3, p4]
+
+        self.create_branch('org/project2', 'stable/havana')
+        self.create_branch('org/project4', 'stable/havana')
+        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
+        B = self.fake_gerrit.addFakeChange('org/project2', 'stable/havana',
+                                           'B')
+        C = self.fake_gerrit.addFakeChange('org/project3', 'master', 'C')
+        A.addApproval('code-review', 2)
+        B.addApproval('code-review', 2)
+        C.addApproval('code-review', 2)
+        self.fake_gerrit.addEvent(A.addApproval('approved', 1))
+        self.fake_gerrit.addEvent(B.addApproval('approved', 1))
+        self.fake_gerrit.addEvent(C.addApproval('approved', 1))
+
+        self.waitUntilSettled()
+
+        self.assertEquals(3, len(self.builds), "Three builds are running")
+
+        upstream = self.getUpstreamRepos(projects)
+        states = [
+            {p1: dict(present=[A], absent=[B, C], branch='master'),
+             p2: dict(commit=str(upstream[p2].commit('master')),
+                      branch='master'),
+             p3: dict(commit=str(upstream[p3].commit('master')),
+                      branch='master'),
+             p4: dict(commit=str(upstream[p4].commit('master')),
+                      branch='master'),
+             },
+            {p1: dict(present=[A], absent=[B, C], branch='master'),
+             p2: dict(present=[B], absent=[A, C], branch='stable/havana'),
+             p3: dict(commit=str(upstream[p3].commit('master')),
+                      branch='master'),
+             p4: dict(commit=str(upstream[p4].commit('stable/havana')),
+                      branch='stable/havana'),
+             },
+            {p1: dict(present=[A], absent=[B, C], branch='master'),
+             p2: dict(commit=str(upstream[p2].commit('master')),
+                      branch='master'),
+             p3: dict(present=[C], absent=[A, B], branch='master'),
+             p4: dict(commit=str(upstream[p4].commit('master')),
+                      branch='master'),
+             },
+        ]
+
+        for number, build in enumerate(self.builds):
+            self.log.debug("Build parameters: %s", build.parameters)
+            work = build.getWorkspaceRepos(projects)
+            state = states[number]
+
+            for project in projects:
+                self.assertRepoState(work[project], state[project],
+                                     project, build, number)
+
+        self.executor_server.hold_jobs_in_build = False
+        self.executor_server.release()
+        self.waitUntilSettled()
+
+    @simple_layout('layouts/repo-checkout-six-project.yaml')
+    def test_project_override(self):
+        self.executor_server.hold_jobs_in_build = True
+
+        p1 = 'review.example.com/org/project1'
+        p2 = 'review.example.com/org/project2'
+        p3 = 'review.example.com/org/project3'
+        p4 = 'review.example.com/org/project4'
+        p5 = 'review.example.com/org/project5'
+        p6 = 'review.example.com/org/project6'
+        projects = [p1, p2, p3, p4, p5, p6]
+
+        self.create_branch('org/project3', 'stable/havana')
+        self.create_branch('org/project4', 'stable/havana')
+        self.create_branch('org/project6', 'stable/havana')
+        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
+        B = self.fake_gerrit.addFakeChange('org/project1', 'master', 'B')
+        C = self.fake_gerrit.addFakeChange('org/project2', 'master', 'C')
+        D = self.fake_gerrit.addFakeChange('org/project3', 'stable/havana',
+                                           'D')
+        A.addApproval('code-review', 2)
+        B.addApproval('code-review', 2)
+        C.addApproval('code-review', 2)
+        D.addApproval('code-review', 2)
+        self.fake_gerrit.addEvent(A.addApproval('approved', 1))
+        self.fake_gerrit.addEvent(B.addApproval('approved', 1))
+        self.fake_gerrit.addEvent(C.addApproval('approved', 1))
+        self.fake_gerrit.addEvent(D.addApproval('approved', 1))
+
+        self.waitUntilSettled()
+
+        self.assertEquals(4, len(self.builds), "Four builds are running")
+
+        upstream = self.getUpstreamRepos(projects)
+        states = [
+            {p1: dict(present=[A], absent=[B, C, D], branch='master'),
+             p2: dict(commit=str(upstream[p2].commit('master')),
+                      branch='master'),
+             p3: dict(commit=str(upstream[p3].commit('master')),
+                      branch='master'),
+             p4: dict(commit=str(upstream[p4].commit('master')),
+                      branch='master'),
+             p5: dict(commit=str(upstream[p5].commit('master')),
+                      branch='master'),
+             p6: dict(commit=str(upstream[p6].commit('master')),
+                      branch='master'),
+             },
+            {p1: dict(present=[A, B], absent=[C, D], branch='master'),
+             p2: dict(commit=str(upstream[p2].commit('master')),
+                      branch='master'),
+             p3: dict(commit=str(upstream[p3].commit('master')),
+                      branch='master'),
+             p4: dict(commit=str(upstream[p4].commit('master')),
+                      branch='master'),
+             p5: dict(commit=str(upstream[p5].commit('master')),
+                      branch='master'),
+             p6: dict(commit=str(upstream[p6].commit('master')),
+                      branch='master'),
+             },
+            {p1: dict(present=[A, B], absent=[C, D], branch='master'),
+             p2: dict(present=[C], absent=[A, B, D], branch='master'),
+             p3: dict(commit=str(upstream[p3].commit('master')),
+                      branch='master'),
+             p4: dict(commit=str(upstream[p4].commit('master')),
+                      branch='master'),
+             p5: dict(commit=str(upstream[p5].commit('master')),
+                      branch='master'),
+             p6: dict(commit=str(upstream[p6].commit('master')),
+                      branch='master'),
+             },
+            {p1: dict(present=[A, B], absent=[C, D], branch='master'),
+             p2: dict(present=[C], absent=[A, B, D], branch='master'),
+             p3: dict(present=[D], absent=[A, B, C],
+                      branch='stable/havana'),
+             p4: dict(commit=str(upstream[p4].commit('master')),
+                      branch='master'),
+             p5: dict(commit=str(upstream[p5].commit('master')),
+                      branch='master'),
+             p6: dict(commit=str(upstream[p6].commit('stable/havana')),
+                      branch='stable/havana'),
+             },
+        ]
+
+        for number, build in enumerate(self.builds):
+            self.log.debug("Build parameters: %s", build.parameters)
+            work = build.getWorkspaceRepos(projects)
+            state = states[number]
+
+            for project in projects:
+                self.assertRepoState(work[project], state[project],
+                                     project, build, number)
+
+        self.executor_server.hold_jobs_in_build = False
+        self.executor_server.release()
+        self.waitUntilSettled()
+
+    def test_periodic(self):
+        # This test can not use simple_layout because it must start
+        # with a configuration which does not include a
+        # timer-triggered job so that we have an opportunity to set
+        # the hold flag before the first job.
+        self.executor_server.hold_jobs_in_build = True
+        # Start timer trigger - also org/project
+        self.commitConfigUpdate('common-config',
+                                'layouts/repo-checkout-timer.yaml')
+        self.sched.reconfigure(self.config)
+
+        p1 = 'review.example.com/org/project1'
+        projects = [p1]
+        self.create_branch('org/project1', 'stable/havana')
+
+        # The pipeline triggers every second, so we should have seen
+        # several by now.
+        time.sleep(5)
+        self.waitUntilSettled()
+
+        # Stop queuing timer triggered jobs so that the assertions
+        # below don't race against more jobs being queued.
+        self.commitConfigUpdate('common-config',
+                                'layouts/repo-checkout-no-timer.yaml')
+        self.sched.reconfigure(self.config)
+
+        self.assertEquals(1, len(self.builds), "One build is running")
+
+        upstream = self.getUpstreamRepos(projects)
+        states = [
+            {p1: dict(commit=str(upstream[p1].commit('stable/havana')),
+                      branch='stable/havana'),
+             },
+        ]
+
+        for number, build in enumerate(self.builds):
+            self.log.debug("Build parameters: %s", build.parameters)
+            work = build.getWorkspaceRepos(projects)
+            state = states[number]
+
+            for project in projects:
+                self.assertRepoState(work[project], state[project],
+                                     project, build, number)
+
+        self.executor_server.hold_jobs_in_build = False
+        self.executor_server.release()
+        self.waitUntilSettled()
+
+    @simple_layout('layouts/repo-checkout-post.yaml')
+    def test_post_and_master_checkout(self):
+        self.executor_server.hold_jobs_in_build = True
+        p1 = "review.example.com/org/project1"
+        p2 = "review.example.com/org/project2"
+        projects = [p1, p2]
+
+        A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
+        event = A.getRefUpdatedEvent()
+        A.setMerged()
+        self.fake_gerrit.addEvent(event)
+        self.waitUntilSettled()
+
+        upstream = self.getUpstreamRepos(projects)
+        states = [
+            {p1: dict(commit=str(upstream[p1].commit('master')),
+                      present=[A], branch='master'),
+             p2: dict(commit=str(upstream[p2].commit('master')),
+                      absent=[A], branch='master'),
+             },
+        ]
+
+        for number, build in enumerate(self.builds):
+            self.log.debug("Build parameters: %s", build.parameters)
+            work = build.getWorkspaceRepos(projects)
+            state = states[number]
+
+            for project in projects:
+                self.assertRepoState(work[project], state[project],
+                                     project, build, number)
+
+        self.executor_server.hold_jobs_in_build = False
+        self.executor_server.release()
+        self.waitUntilSettled()
diff --git a/tests/unit/test_github_driver.py b/tests/unit/test_github_driver.py
index 227d659..6cc010e 100644
--- a/tests/unit/test_github_driver.py
+++ b/tests/unit/test_github_driver.py
@@ -300,6 +300,9 @@
         self.assertEqual('tenant-one/reporting', report_status['context'])
         self.assertEqual('success', report_status['state'])
         self.assertEqual(2, len(A.comments))
+        report_url = ('http://logs.example.com/reporting/%s/%s/%s/' %
+                      (A.project, A.number, A.head_sha))
+        self.assertEqual(report_url, report_status['url'])
 
     @simple_layout('layouts/merging-github.yaml', driver='github')
     def test_report_pull_merge(self):
diff --git a/tests/unit/test_model.py b/tests/unit/test_model.py
index 5f968b4..e7e53c4 100644
--- a/tests/unit/test_model.py
+++ b/tests/unit/test_model.py
@@ -106,7 +106,7 @@
         base.auth = model.AuthContext()
 
         py27 = model.Job('py27')
-        self.assertEqual(None, py27.timeout)
+        self.assertIsNone(py27.timeout)
         py27.inheritFrom(base)
         self.assertEqual(30, py27.timeout)
         self.assertEqual(['base-pre'],
@@ -115,7 +115,7 @@
                          [x.path for x in py27.run])
         self.assertEqual(['base-post'],
                          [x.path for x in py27.post_run])
-        self.assertEqual(None, py27.auth)
+        self.assertIsNone(py27.auth)
 
     def test_job_variants(self):
         # This simulates freezing a job.
@@ -433,11 +433,11 @@
             })
         layout.addJob(in_repo_job_with_inherit_false)
 
-        self.assertEqual(None, in_repo_job_without_inherit.auth)
+        self.assertIsNone(in_repo_job_without_inherit.auth)
         self.assertEqual(1, len(in_repo_job_with_inherit.auth.secrets))
         self.assertEqual(in_repo_job_with_inherit.auth.secrets[0].name,
                          'pypi-credentials')
-        self.assertEqual(None, in_repo_job_with_inherit_false.auth)
+        self.assertIsNone(in_repo_job_with_inherit_false.auth)
 
     def test_job_inheritance_job_tree(self):
         tenant = model.Tenant('tenant')
diff --git a/tests/unit/test_scheduler.py b/tests/unit/test_scheduler.py
index 9cc5e60..0ac42c1 100755
--- a/tests/unit/test_scheduler.py
+++ b/tests/unit/test_scheduler.py
@@ -63,7 +63,11 @@
         self.assertIsNone(self.getJobFromHistory('project-test2').node)
 
         # TODOv3(jeblair): we may want to report stats by tenant (also?).
-        self.assertReportedStat('gerrit.event.comment-added', value='1|c')
+        # Per-driver
+        self.assertReportedStat('zuul.event.gerrit.comment-added', value='1|c')
+        # Per-driver per-connection
+        self.assertReportedStat('zuul.event.gerrit.gerrit.comment-added',
+                                value='1|c')
         self.assertReportedStat('zuul.pipeline.gate.current_changes',
                                 value='1|g')
         self.assertReportedStat('zuul.pipeline.gate.job.project-merge.SUCCESS',
@@ -3545,9 +3549,9 @@
         self.assertEqual([], running_item['failing_reasons'])
         self.assertEqual([], running_item['items_behind'])
         self.assertEqual('https://hostname/1', running_item['url'])
-        self.assertEqual(None, running_item['item_ahead'])
+        self.assertIsNone(running_item['item_ahead'])
         self.assertEqual('org/project', running_item['project'])
-        self.assertEqual(None, running_item['remaining_time'])
+        self.assertIsNone(running_item['remaining_time'])
         self.assertEqual(True, running_item['active'])
         self.assertEqual('1,1', running_item['id'])
 
@@ -3562,7 +3566,7 @@
                 self.assertEqual(7, len(job['worker']))
                 self.assertEqual(False, job['canceled'])
                 self.assertEqual(True, job['voting'])
-                self.assertEqual(None, job['result'])
+                self.assertIsNone(job['result'])
                 self.assertEqual('gate', job['pipeline'])
                 break
 
diff --git a/zuul/connection/__init__.py b/zuul/connection/__init__.py
index 49624d7..90ab39c 100644
--- a/zuul/connection/__init__.py
+++ b/zuul/connection/__init__.py
@@ -14,6 +14,7 @@
 
 import abc
 
+import extras
 import six
 
 
@@ -43,6 +44,26 @@
         self.driver = driver
         self.connection_name = connection_name
         self.connection_config = connection_config
+        self.statsd = extras.try_import('statsd.statsd')
+
+    def logEvent(self, event):
+        self.log.debug(
+            'Scheduling {driver} event from {connection}: {event}'.format(
+                driver=self.driver.name,
+                connection=self.connection_name,
+                event=event.type))
+        try:
+            if self.statsd:
+                self.statsd.incr(
+                    'zuul.event.{driver}.{event}'.format(
+                        driver=self.driver.name, event=event.type))
+                self.statsd.incr(
+                    'zuul.event.{driver}.{connection}.{event}'.format(
+                        driver=self.driver.name,
+                        connection=self.connection_name,
+                        event=event.type))
+        except:
+            self.log.exception("Exception reporting event stats")
 
     def onLoad(self):
         pass
diff --git a/zuul/driver/gerrit/gerritconnection.py b/zuul/driver/gerrit/gerritconnection.py
index 06962e5..a1d97e7 100644
--- a/zuul/driver/gerrit/gerritconnection.py
+++ b/zuul/driver/gerrit/gerritconnection.py
@@ -143,6 +143,7 @@
             self.connection._getChange(event.change_number,
                                        event.patch_number,
                                        refresh=True)
+        self.connection.logEvent(event)
         self.connection.sched.addEvent(event)
 
     def run(self):
@@ -625,7 +626,7 @@
             if val is True:
                 cmd += ' --%s' % key
             else:
-                cmd += ' --%s %s' % (key, val)
+                cmd += ' --label %s=%s' % (key, val)
         cmd += ' %s' % change
         out, err = self._ssh(cmd)
         return err
diff --git a/zuul/driver/github/githubconnection.py b/zuul/driver/github/githubconnection.py
index 02c795e..6a3c09e 100644
--- a/zuul/driver/github/githubconnection.py
+++ b/zuul/driver/github/githubconnection.py
@@ -119,7 +119,7 @@
 
         if event:
             event.project_hostname = self.connection.canonical_hostname
-            self.log.debug('Scheduling github event: {0}'.format(event.type))
+            self.connection.logEvent(event)
             self.connection.sched.addEvent(event)
 
     def _event_push(self, body):
diff --git a/zuul/driver/github/githubreporter.py b/zuul/driver/github/githubreporter.py
index 68c6af0..fc3b64d 100644
--- a/zuul/driver/github/githubreporter.py
+++ b/zuul/driver/github/githubreporter.py
@@ -70,12 +70,14 @@
         sha = item.change.patchset
         context = '%s/%s' % (pipeline.layout.tenant.name, pipeline.name)
         state = self._commit_status
-        url = ''
-        if self.connection.sched.config.has_option('zuul', 'status_url'):
-            base = self.connection.sched.config.get('zuul', 'status_url')
-            url = '%s/#%s,%s' % (base,
-                                 item.change.number,
-                                 item.change.patchset)
+
+        url_pattern = self.config.get('status-url')
+        if not url_pattern:
+            sched_config = self.connection.sched.config
+            if sched_config.has_option('zuul', 'status_url'):
+                url_pattern = sched_config.get('zuul', 'status_url')
+        url = item.formatUrlPattern(url_pattern) if url_pattern else ''
+
         description = ''
         if pipeline.description:
             description = pipeline.description
@@ -157,6 +159,7 @@
 def getSchema():
     github_reporter = v.Schema({
         'status': v.Any('pending', 'success', 'failure'),
+        'status-url': str,
         'comment': bool,
         'merge': bool,
         'label': scalar_or_list(str),
diff --git a/zuul/driver/sql/sqlreporter.py b/zuul/driver/sql/sqlreporter.py
index 46d538a..349abe8 100644
--- a/zuul/driver/sql/sqlreporter.py
+++ b/zuul/driver/sql/sqlreporter.py
@@ -39,13 +39,16 @@
             return
 
         with self.connection.engine.begin() as conn:
+            change = getattr(item.change, 'number', '')
+            patchset = getattr(item.change, 'patchset', '')
+            refspec = getattr(item.change, 'refspec', item.change.newrev)
             buildset_ins = self.connection.zuul_buildset_table.insert().values(
                 zuul_ref=item.current_build_set.ref,
                 pipeline=item.pipeline.name,
                 project=item.change.project.name,
-                change=item.change.number,
-                patchset=item.change.patchset,
-                ref=item.change.refspec,
+                change=change,
+                patchset=patchset,
+                ref=refspec,
                 score=self.result_score,
                 message=self._formatItemReport(
                     pipeline, item, with_jobs=False),
diff --git a/zuul/executor/client.py b/zuul/executor/client.py
index 907cce5..cf8d973 100644
--- a/zuul/executor/client.py
+++ b/zuul/executor/client.py
@@ -261,6 +261,10 @@
         params['timeout'] = job.timeout
         params['items'] = merger_items
         params['projects'] = []
+        if hasattr(item.change, 'branch'):
+            params['branch'] = item.change.branch
+        else:
+            params['branch'] = None
         params['override_branch'] = job.override_branch
         params['repo_state'] = item.current_build_set.repo_state
 
@@ -300,6 +304,7 @@
             connection = project.source.connection
             return dict(connection=connection.connection_name,
                         name=project.name,
+                        canonical_name=project.canonical_name,
                         override_branch=override_branch,
                         default_branch=project_default_branch)
 
diff --git a/zuul/executor/server.py b/zuul/executor/server.py
index 2b67f95..5323c21 100644
--- a/zuul/executor/server.py
+++ b/zuul/executor/server.py
@@ -27,7 +27,6 @@
 from zuul.lib.yamlutil import yaml
 
 import gear
-import git
 from six.moves import shlex_quote
 
 import zuul.merger.merger
@@ -435,9 +434,14 @@
 
         self.job_workers = {}
 
-    def _getMerger(self, root):
+    def _getMerger(self, root, logger=None):
+        if root != self.merge_root:
+            cache_root = self.merge_root
+        else:
+            cache_root = None
         return zuul.merger.merger.Merger(root, self.connections,
-                                         self.merge_email, self.merge_name)
+                                         self.merge_email, self.merge_name,
+                                         cache_root, logger)
 
     def start(self):
         self._running = True
@@ -653,19 +657,27 @@
         if ret is None:
             result['commit'] = result['files'] = result['repo_state'] = None
         else:
-            result['commit'], result['files'], result['repo_state'] = ret
+            (result['commit'], result['files'], result['repo_state'],
+             recent) = ret
         job.sendWorkComplete(json.dumps(result))
 
 
-class AnsibleJob(object):
-    log = logging.getLogger("zuul.AnsibleJob")
+class AnsibleJobLogAdapter(logging.LoggerAdapter):
+    def process(self, msg, kwargs):
+        msg, kwargs = super(AnsibleJobLogAdapter, self).process(msg, kwargs)
+        msg = '[build: %s] %s' % (kwargs['extra']['job'], msg)
+        return msg, kwargs
 
+
+class AnsibleJob(object):
     RESULT_NORMAL = 1
     RESULT_TIMED_OUT = 2
     RESULT_UNREACHABLE = 3
     RESULT_ABORTED = 4
 
     def __init__(self, executor_server, job):
+        logger = logging.getLogger("zuul.AnsibleJob")
+        self.log = AnsibleJobLogAdapter(logger, {'job': job.unique})
         self.executor_server = executor_server
         self.job = job
         self.jobdir = None
@@ -739,36 +751,37 @@
             task.wait()
 
         self.log.debug("Job %s: git updates complete" % (self.job.unique,))
-        repos = []
+        merger = self.executor_server._getMerger(self.jobdir.src_root,
+                                                 self.log)
+        repos = {}
         for project in args['projects']:
             self.log.debug("Cloning %s/%s" % (project['connection'],
                                               project['name'],))
-            source = self.executor_server.connections.getSource(
-                project['connection'])
-            project_object = source.getProject(project['name'])
-            url = source.getGitUrl(project_object)
-            repo = git.Repo.clone_from(
-                os.path.join(self.executor_server.merge_root,
-                             source.canonical_hostname,
-                             project['name']),
-                os.path.join(self.jobdir.src_root,
-                             source.canonical_hostname,
-                             project['name']))
-
-            repo.remotes.origin.config_writer.set('url', url)
-            repos.append(repo)
+            repo = merger.getRepo(project['connection'],
+                                  project['name'])
+            repos[project['canonical_name']] = repo
 
         merge_items = [i for i in args['items'] if i.get('refspec')]
         if merge_items:
-            if not self.doMergeChanges(merge_items, args['repo_state']):
+            if not self.doMergeChanges(merger, merge_items,
+                                       args['repo_state']):
                 # There was a merge conflict and we have already sent
                 # a work complete result, don't run any jobs
                 return
 
+        for project in args['projects']:
+            repo = repos[project['canonical_name']]
+            self.checkoutBranch(repo,
+                                project['name'],
+                                args['branch'],
+                                args['override_branch'],
+                                project['override_branch'],
+                                project['default_branch'])
+
         # Delete the origin remote from each repo we set up since
         # it will not be valid within the jobs.
-        for repo in repos:
-            repo.delete_remote(repo.remotes.origin)
+        for repo in repos.values():
+            repo.deleteRemote('origin')
 
         # is the playbook in a repo that we have already prepared?
         trusted, untrusted = self.preparePlaybookRepos(args)
@@ -806,16 +819,43 @@
         result = dict(result=result)
         self.job.sendWorkComplete(json.dumps(result))
 
-    def doMergeChanges(self, items, repo_state):
-        # Get a merger in order to update the repos involved in this job.
-        merger = self.executor_server._getMerger(self.jobdir.src_root)
+    def doMergeChanges(self, merger, items, repo_state):
         ret = merger.mergeChanges(items, repo_state=repo_state)
         if not ret:  # merge conflict
             result = dict(result='MERGER_FAILURE')
             self.job.sendWorkComplete(json.dumps(result))
             return False
+        recent = ret[3]
+        for key, commit in recent.items():
+            (connection, project, branch) = key
+            repo = merger.getRepo(connection, project)
+            repo.setRef('refs/heads/' + branch, commit)
         return True
 
+    def checkoutBranch(self, repo, project_name, zuul_branch,
+                       job_branch, project_override_branch,
+                       project_default_branch):
+        branches = repo.getBranches()
+        if project_override_branch in branches:
+            self.log.info("Checking out %s project override branch %s",
+                          project_name, project_override_branch)
+            repo.checkoutLocalBranch(project_override_branch)
+        elif job_branch in branches:
+            self.log.info("Checking out %s job branch %s",
+                          project_name, job_branch)
+            repo.checkoutLocalBranch(job_branch)
+        elif zuul_branch and zuul_branch in branches:
+            self.log.info("Checking out %s zuul branch %s",
+                          project_name, zuul_branch)
+            repo.checkoutLocalBranch(zuul_branch)
+        elif project_default_branch in branches:
+            self.log.info("Checking out %s project default branch %s",
+                          project_name, project_default_branch)
+            repo.checkoutLocalBranch(project_default_branch)
+        else:
+            raise Exception("Project %s does not have the default branch %s" %
+                            (project_name, project_default_branch))
+
     def runPlaybooks(self, args):
         result = None
 
@@ -971,7 +1011,8 @@
         # the stack of changes we are testing, so check out the branch
         # tip into a dedicated space.
 
-        merger = self.executor_server._getMerger(jobdir_playbook.root)
+        merger = self.executor_server._getMerger(jobdir_playbook.root,
+                                                 self.log)
         merger.checkoutBranch(playbook['connection'], project.name,
                               playbook['branch'])
 
@@ -1055,7 +1096,8 @@
             # in the dependency chain for the change (in which case,
             # there is no existing untrusted checkout of it).  Check
             # out the branch tip into a dedicated space.
-            merger = self.executor_server._getMerger(trusted_root)
+            merger = self.executor_server._getMerger(trusted_root,
+                                                     self.log)
             merger.checkoutBranch(role['connection'], project.name,
                                   'master')
             orig_repo_path = os.path.join(trusted_root,
diff --git a/zuul/lib/log_streamer.py b/zuul/lib/log_streamer.py
index 6aa51a6..de072b6 100644
--- a/zuul/lib/log_streamer.py
+++ b/zuul/lib/log_streamer.py
@@ -47,8 +47,39 @@
     the (class/method/attribute) names were changed to protect the innocent.
     '''
 
+    MAX_REQUEST_LEN = 1024
+    REQUEST_TIMEOUT = 10
+
+    def get_command(self):
+        poll = select.poll()
+        bitmask = (select.POLLIN | select.POLLERR |
+                   select.POLLHUP | select.POLLNVAL)
+        poll.register(self.request, bitmask)
+        buffer = b''
+        ret = None
+        start = time.time()
+        while True:
+            elapsed = time.time() - start
+            timeout = max(self.REQUEST_TIMEOUT - elapsed, 0)
+            if not timeout:
+                raise Exception("Timeout while waiting for input")
+            for fd, event in poll.poll(timeout):
+                if event & select.POLLIN:
+                    buffer += self.request.recv(self.MAX_REQUEST_LEN)
+                else:
+                    raise Exception("Received error event")
+            if len(buffer) >= self.MAX_REQUEST_LEN:
+                raise Exception("Request too long")
+            try:
+                ret = buffer.decode('utf-8')
+                x = ret.find('\n')
+                if x > 0:
+                    return ret[:x]
+            except UnicodeDecodeError:
+                pass
+
     def handle(self):
-        build_uuid = self.request.recv(1024).decode("utf-8")
+        build_uuid = self.get_command()
         build_uuid = build_uuid.rstrip()
 
         # validate build ID
diff --git a/zuul/merger/merger.py b/zuul/merger/merger.py
index ee83fa0..6cfd904 100644
--- a/zuul/merger/merger.py
+++ b/zuul/merger/merger.py
@@ -42,13 +42,17 @@
 
 
 class Repo(object):
-    log = logging.getLogger("zuul.Repo")
-
-    def __init__(self, remote, local, email, username):
+    def __init__(self, remote, local, email, username,
+                 cache_path=None, logger=None):
+        if logger is None:
+            self.log = logging.getLogger("zuul.Repo")
+        else:
+            self.log = logger
         self.remote_url = remote
         self.local_path = local
         self.email = email
         self.username = username
+        self.cache_path = cache_path
         self._initialized = False
         try:
             self._ensure_cloned()
@@ -60,17 +64,32 @@
         if self._initialized and repo_is_cloned:
             return
         # If the repo does not exist, clone the repo.
+        rewrite_url = False
         if not repo_is_cloned:
             self.log.debug("Cloning from %s to %s" % (self.remote_url,
                                                       self.local_path))
-            git.Repo.clone_from(self.remote_url, self.local_path)
+            if self.cache_path:
+                git.Repo.clone_from(self.cache_path, self.local_path)
+                rewrite_url = True
+            else:
+                git.Repo.clone_from(self.remote_url, self.local_path)
         repo = git.Repo(self.local_path)
+        # Create local branches corresponding to all the remote branches
+        if not repo_is_cloned:
+            origin = repo.remotes.origin
+            for ref in origin.refs:
+                if ref.remote_head == 'HEAD':
+                    continue
+                repo.create_head(ref.remote_head, ref, force=True)
         with repo.config_writer() as config_writer:
             if self.email:
                 config_writer.set_value('user', 'email', self.email)
             if self.username:
                 config_writer.set_value('user', 'name', self.username)
             config_writer.write()
+        if rewrite_url:
+            with repo.remotes.origin.config_writer as config_writer:
+                config_writer.set('url', self.remote_url)
         self._initialized = True
 
     def isInitialized(self):
@@ -118,6 +137,10 @@
         origin = repo.remotes.origin
         return branch in origin.refs
 
+    def getBranches(self):
+        repo = self.createRepoObject()
+        return [x.name for x in repo.heads]
+
     def getCommitFromRef(self, refname):
         repo = self.createRepoObject()
         if refname not in repo.refs:
@@ -129,6 +152,14 @@
         repo = self.createRepoObject()
         return repo.refs
 
+    def setRef(self, path, hexsha, repo=None):
+        if repo is None:
+            repo = self.createRepoObject()
+        binsha = gitdb.util.to_bin_sha(hexsha)
+        obj = git.objects.Object.new_from_sha(repo, binsha)
+        self.log.debug("Create reference %s", path)
+        git.refs.Reference.create(repo, path, obj, force=True)
+
     def setRefs(self, refs):
         repo = self.createRepoObject()
         current_refs = {}
@@ -136,10 +167,7 @@
             current_refs[ref.path] = ref
         unseen = set(current_refs.keys())
         for path, hexsha in refs.items():
-            binsha = gitdb.util.to_bin_sha(hexsha)
-            obj = git.objects.Object.new_from_sha(repo, binsha)
-            self.log.debug("Create reference %s", path)
-            git.refs.Reference.create(repo, path, obj, force=True)
+            self.setRef(path, hexsha, repo)
             unseen.discard(path)
         for path in unseen:
             self.log.debug("Delete reference %s", path)
@@ -152,6 +180,13 @@
         reset_repo_to_head(repo)
         return repo.head.commit
 
+    def checkoutLocalBranch(self, branch):
+        repo = self.createRepoObject()
+        # Perform a hard reset before checking out so that we clean up
+        # anything that might be left over from a merge.
+        reset_repo_to_head(repo)
+        repo.heads[branch].checkout()
+
     def cherryPick(self, ref):
         repo = self.createRepoObject()
         self.log.debug("Cherry-picking %s" % ref)
@@ -225,11 +260,19 @@
                 ret[fn] = None
         return ret
 
+    def deleteRemote(self, remote):
+        repo = self.createRepoObject()
+        repo.delete_remote(repo.remotes[remote])
+
 
 class Merger(object):
-    log = logging.getLogger("zuul.Merger")
-
-    def __init__(self, working_root, connections, email, username):
+    def __init__(self, working_root, connections, email, username,
+                 cache_root=None, logger=None):
+        self.logger = logger
+        if logger is None:
+            self.log = logging.getLogger("zuul.Merger")
+        else:
+            self.log = logger
         self.repos = {}
         self.working_root = working_root
         if not os.path.exists(working_root):
@@ -237,6 +280,7 @@
         self.connections = connections
         self.email = email
         self.username = username
+        self.cache_root = cache_root
 
     def _get_ssh_cmd(self, connection_name):
         sshkey = self.connections.connections.get(connection_name).\
@@ -259,7 +303,13 @@
         key = '/'.join([hostname, project_name])
         try:
             path = os.path.join(self.working_root, hostname, project_name)
-            repo = Repo(url, path, self.email, self.username)
+            if self.cache_root:
+                cache_path = os.path.join(self.cache_root, hostname,
+                                          project_name)
+            else:
+                cache_path = None
+            repo = Repo(url, path, self.email, self.username, cache_path,
+                        self.logger)
 
             self.repos[key] = repo
         except Exception:
@@ -296,28 +346,25 @@
                                connection_name, project_name)
 
     def checkoutBranch(self, connection_name, project_name, branch):
+        self.log.info("Checking out %s/%s branch %s",
+                      connection_name, project_name, branch)
         repo = self.getRepo(connection_name, project_name)
-        if repo.hasBranch(branch):
-            self.log.info("Checking out branch %s of %s/%s" %
-                          (branch, connection_name, project_name))
-            head = repo.getBranchHead(branch)
-            repo.checkout(head)
-        else:
-            raise Exception("Project %s/%s does not have branch %s" %
-                            (connection_name, project_name, branch))
+        repo.checkoutLocalBranch(branch)
 
     def _saveRepoState(self, connection_name, project_name, repo,
-                       repo_state):
+                       repo_state, recent):
         projects = repo_state.setdefault(connection_name, {})
         project = projects.setdefault(project_name, {})
-        if project:
-            # We already have a state for this project.
-            return
         for ref in repo.getRefs():
-            if ref.path.startswith('refs/zuul'):
+            if ref.path.startswith('refs/zuul/'):
                 continue
-            if ref.path.startswith('refs/remotes'):
+            if ref.path.startswith('refs/remotes/'):
                 continue
+            if ref.path.startswith('refs/heads/'):
+                branch = ref.path[len('refs/heads/'):]
+                key = (connection_name, project_name, branch)
+                if key not in recent:
+                    recent[key] = ref.object
             project[ref.path] = ref.object.hexsha
 
     def _restoreRepoState(self, connection_name, project_name, repo,
@@ -386,7 +433,7 @@
             # Save the repo state so that later mergers can repeat
             # this process.
             self._saveRepoState(item['connection'], item['project'], repo,
-                                repo_state)
+                                repo_state, recent)
         else:
             self.log.debug("Found base commit %s for %s" % (base, key,))
         # Merge the change
@@ -439,7 +486,10 @@
                     project=item['project'],
                     branch=item['branch'],
                     files=repo_files))
-        return commit.hexsha, read_files, repo_state
+        ret_recent = {}
+        for k, v in recent.items():
+            ret_recent[k] = v.hexsha
+        return commit.hexsha, read_files, repo_state, ret_recent
 
     def getFiles(self, connection_name, project_name, branch, files):
         repo = self.getRepo(connection_name, project_name)
diff --git a/zuul/merger/server.py b/zuul/merger/server.py
index 15f1a41..1a32f96 100644
--- a/zuul/merger/server.py
+++ b/zuul/merger/server.py
@@ -110,7 +110,8 @@
         if ret is None:
             result['commit'] = result['files'] = result['repo_state'] = None
         else:
-            result['commit'], result['files'], result['repo_state'] = ret
+            (result['commit'], result['files'], result['repo_state'],
+             recent) = ret
         job.sendWorkComplete(json.dumps(result))
 
     def cat(self, job):
diff --git a/zuul/model.py b/zuul/model.py
index b468bbf..6ad34ff 100644
--- a/zuul/model.py
+++ b/zuul/model.py
@@ -1588,8 +1588,8 @@
         # secrets, etc.
         safe_change = self.change.getSafeAttributes()
         safe_pipeline = self.pipeline.getSafeAttributes()
-        safe_job = job.getSafeAttributes()
-        safe_build = build.getSafeAttributes()
+        safe_job = job.getSafeAttributes() if job else {}
+        safe_build = build.getSafeAttributes() if build else {}
         try:
             url = url_pattern.format(change=safe_change,
                                      pipeline=safe_pipeline,
diff --git a/zuul/scheduler.py b/zuul/scheduler.py
index 40d5eb7..61f1e5f 100644
--- a/zuul/scheduler.py
+++ b/zuul/scheduler.py
@@ -258,11 +258,6 @@
 
     def addEvent(self, event):
         self.log.debug("Adding trigger event: %s" % event)
-        try:
-            if self.statsd:
-                self.statsd.incr('gerrit.event.%s' % event.type)
-        except:
-            self.log.exception("Exception reporting event stats")
         self.trigger_event_queue.put(event)
         self.wake_event.set()
         self.log.debug("Done adding trigger event: %s" % event)