ci: One Tox environment per Azure job

.ci/azure-pipelines-steps.yml

@@ -10,7 +10,18 @@ steps:
   inputs:
     versionSpec: '$(python.version)'
 
-- script: python -mpip install tox
+- task: Cache@2
+  displayName: Cache pip packages
+  inputs:
+    key: python | "$(Agent.OS)" | tox.ini | tests/requirements.txt | tests/ansible/requirements.txt
+    restoreKeys: |
+      python | "$(Agent.OS)" | tox.ini | tests/requirements.txt
+      python | "$(Agent.OS)" | tox.ini
+      python | "$(Agent.OS)"
+      python
+    path: $(PIP_CACHE_DIR)
+
+- script: python -mpip --no-python-version-warning --disable-pip-version-check install tox==3.24.4
   displayName: Install tooling
 
 - script: tox -e "$(tox.env)"

.ci/azure-pipelines.yml

@@ -5,8 +5,9 @@
 
 # User defined variables are also injected as environment variables
 # https://docs.microsoft.com/en-us/azure/devops/pipelines/process/variables#environment-variables
-#variables:
+variables:
   #ANSIBLE_VERBOSITY: 3
+  PIP_CACHE_DIR: $(Pipeline.Workspace)/.pip
 
 jobs:
 
@@ -20,22 +21,78 @@ jobs:
     vmImage: macOS-10.15
   strategy:
     matrix:
-      Mito27_27:
+      Py27Localhost2.10:
+        python.version: '2.7'
+        tox.env: py27-mode_localhost-ansible2.10
+      Py27Localhost3:
+        python.version: '2.7'
+        tox.env: py27-mode_localhost-ansible3
+      Py27Localhost4:
+        python.version: '2.7'
+        tox.env: py27-mode_localhost-ansible4
+      Py27Mitogen:
         python.version: '2.7'
         tox.env: py27-mode_mitogen
-
+      Py27Vanilla2.10:
-      # TODO: test python3, python3 tests are broken
+        ANSIBLE_SKIP_TAGS: resource_intensive
-      Local_Py27:
         python.version: '2.7'
-        tox.env: py27-mode_localhost-ansible{2.10,3,4}
+        tox.env: py27-mode_localhost-ansible2.10-strategy_linear
-
+      Py27Vanilla3:
-      # NOTE: this hangs when ran in Ubuntu 18.04
+        ANSIBLE_SKIP_TAGS: resource_intensive
-      Vanilla_Py27:
         python.version: '2.7'
-        tox.env: py27-mode_localhost-ansible{2.10,3,4}
+        tox.env: py27-mode_localhost-ansible3-strategy_linear
-        STRATEGY: linear
+      Py27Vanilla4:
         ANSIBLE_SKIP_TAGS: resource_intensive
-
+        python.version: '2.7'
+        tox.env: py27-mode_localhost-ansible4-strategy_linear
+      Py36Localhost2.10:
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible2.10
+      Py36Localhost3:
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible3
+      Py36Localhost4:
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible4
+      Py36Mitogen:
+        python.version: '3.6'
+        tox.env: py36-mode_mitogen
+      Py36Vanilla2.10:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible2.10-strategy_linear
+      Py36Vanilla3:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible3-strategy_linear
+      Py36Vanilla4:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible4-strategy_linear
+      Py39Localhost2.10:
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible2.10
+      Py39Localhost3:
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible3
+      Py39Localhost4:
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible4
+      Py39Mitogen:
+        python.version: '3.9'
+        tox.env: py39-mode_mitogen
+      Py39Vanilla2.10:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible2.10-strategy_linear
+      Py39Vanilla3:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible3-strategy_linear
+      Py39Vanilla4:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible4-strategy_linear
 
 - job: Linux
   pool:
@@ -45,63 +102,204 @@ jobs:
   - template: azure-pipelines-steps.yml
   strategy:
     matrix:
-      Mito_Py27:
-        python.version: '2.7'
-        tox.env: py27-mode_mitogen-distro_{centos6,centos7,centos8,debian9,debian10,debian11,ubuntu1604,ubuntu1804,ubuntu2004}
-
-      Mito_Py36:
-        python.version: '3.6'
-        tox.env: py36-mode_mitogen-distro_{centos6,centos7,centos8,debian9,debian10,debian11,ubuntu1604,ubuntu1804,ubuntu2004}
-
-      Mito_Py39:
-        python.version: '3.9'
-        tox.env: py39-mode_mitogen-distro_{centos6,centos7,centos8,debian9,debian10,debian11,ubuntu1604,ubuntu1804,ubuntu2004}
-
       #DebOps_2460_27_27:
         #python.version: '2.7'
         #MODE: debops_common
         #VER: 2.4.6.0
-
       #DebOps_262_36_27:
         #python.version: '3.6'
         #MODE: debops_common
         #VER: 2.6.2
-
       #Ansible_2460_26:
         #python.version: '2.7'
         #MODE: ansible
         #VER: 2.4.6.0
-
       #Ansible_262_26:
         #python.version: '2.7'
         #MODE: ansible
         #VER: 2.6.2
-
       #Ansible_2460_36:
         #python.version: '3.6'
         #MODE: ansible
         #VER: 2.4.6.0
-
       #Ansible_262_36:
         #python.version: '3.6'
         #MODE: ansible
         #VER: 2.6.2
-
       #Vanilla_262_27:
         #python.version: '2.7'
         #MODE: ansible
         #VER: 2.6.2
         #DISTROS: debian
-        #STRATEGY: linear
+        #ANSIBLE_STRATEGY: linear
-
+      Py27Ansible2.10:
-      Ansible_Py27:
         python.version: '2.7'
-        tox.env: py27-mode_ansible-ansible{2.10,3,4}
+        tox.env: py27-mode_ansible-ansible2.10
-
+      Py27Ansible3:
-      Ansible_Py36:
+        python.version: '2.7'
+        tox.env: py27-mode_ansible-ansible3
+      Py27Ansible4:
+        python.version: '2.7'
+        tox.env: py27-mode_ansible-ansible4
+      Py27Localhost2.10:
+        python.version: '2.7'
+        tox.env: py27-mode_localhost-ansible2.10
+      Py27Localhost3:
+        python.version: '2.7'
+        tox.env: py27-mode_localhost-ansible3
+      Py27Localhost4:
+        python.version: '2.7'
+        tox.env: py27-mode_localhost-ansible4
+      Py27MitogenCentos6:
+        python.version: '2.7'
+        tox.env: py27-mode_mitogen-distro_centos6
+      Py27MitogenCentos7:
+        python.version: '2.7'
+        tox.env: py27-mode_mitogen-distro_centos7
+      Py27MitogenCentos8:
+        python.version: '2.7'
+        tox.env: py27-mode_mitogen-distro_centos8
+      Py27MitogenDebian10:
+        python.version: '2.7'
+        tox.env: py27-mode_mitogen-distro_debian10
+      Py27MitogenDebian11:
+        python.version: '2.7'
+        tox.env: py27-mode_mitogen-distro_debian11
+      Py27MitogenDebian9:
+        python.version: '2.7'
+        tox.env: py27-mode_mitogen-distro_debian9
+      Py27MitogenUbuntu1604:
+        python.version: '2.7'
+        tox.env: py27-mode_mitogen-distro_ubuntu1604
+      Py27MitogenUbuntu1804:
+        python.version: '2.7'
+        tox.env: py27-mode_mitogen-distro_ubuntu1804
+      Py27MitogenUbuntu2004:
+        python.version: '2.7'
+        tox.env: py27-mode_mitogen-distro_ubuntu2004
+      Py27Vanilla2.10:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '2.7'
+        tox.env: py27-mode_localhost-ansible2.10-strategy_linear
+      Py27Vanilla3:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '2.7'
+        tox.env: py27-mode_localhost-ansible3-strategy_linear
+      Py27Vanilla4:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '2.7'
+        tox.env: py27-mode_localhost-ansible4-strategy_linear
+      Py36Ansible2.10:
         python.version: '3.6'
-        tox.env: py36-mode_ansible-ansible{2.10,3,4}
+        tox.env: py36-mode_ansible-ansible2.10
-
+      Py36Ansible3:
-      Ansible_Py39:
+        python.version: '3.6'
+        tox.env: py36-mode_ansible-ansible3
+      Py36Ansible4:
+        python.version: '3.6'
+        tox.env: py36-mode_ansible-ansible4
+      Py36Localhost2.10:
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible2.10
+      Py36Localhost3:
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible3
+      Py36Localhost4:
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible4
+      Py36MitogenCentos6:
+        python.version: '3.6'
+        tox.env: py36-mode_mitogen-distro_centos6
+      Py36MitogenCentos7:
+        python.version: '3.6'
+        tox.env: py36-mode_mitogen-distro_centos7
+      Py36MitogenCentos8:
+        python.version: '3.6'
+        tox.env: py36-mode_mitogen-distro_centos8
+      Py36MitogenDebian10:
+        python.version: '3.6'
+        tox.env: py36-mode_mitogen-distro_debian10
+      Py36MitogenDebian11:
+        python.version: '3.6'
+        tox.env: py36-mode_mitogen-distro_debian11
+      Py36MitogenDebian9:
+        python.version: '3.6'
+        tox.env: py36-mode_mitogen-distro_debian9
+      Py36MitogenUbuntu1604:
+        python.version: '3.6'
+        tox.env: py36-mode_mitogen-distro_ubuntu1604
+      Py36MitogenUbuntu1804:
+        python.version: '3.6'
+        tox.env: py36-mode_mitogen-distro_ubuntu1804
+      Py36MitogenUbuntu2004:
+        python.version: '3.6'
+        tox.env: py36-mode_mitogen-distro_ubuntu2004
+      Py36Vanilla2.10:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible2.10-strategy_linear
+      Py36Vanilla3:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible3-strategy_linear
+      Py36Vanilla4:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.6'
+        tox.env: py36-mode_localhost-ansible4-strategy_linear
+      Py39Ansible2.10:
+        python.version: '3.9'
+        tox.env: py39-mode_ansible-ansible2.10
+      Py39Ansible3:
+        python.version: '3.9'
+        tox.env: py39-mode_ansible-ansible3
+      Py39Ansible4:
+        python.version: '3.9'
+        tox.env: py39-mode_ansible-ansible4
+      Py39Localhost2.10:
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible2.10
+      Py39Localhost3:
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible3
+      Py39Localhost4:
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible4
+      Py39MitogenCentos6:
+        python.version: '3.9'
+        tox.env: py39-mode_mitogen-distro_centos6
+      Py39MitogenCentos7:
+        python.version: '3.9'
+        tox.env: py39-mode_mitogen-distro_centos7
+      Py39MitogenCentos8:
+        python.version: '3.9'
+        tox.env: py39-mode_mitogen-distro_centos8
+      Py39MitogenDebian10:
+        python.version: '3.9'
+        tox.env: py39-mode_mitogen-distro_debian10
+      Py39MitogenDebian11:
+        python.version: '3.9'
+        tox.env: py39-mode_mitogen-distro_debian11
+      Py39MitogenDebian9:
+        python.version: '3.9'
+        tox.env: py39-mode_mitogen-distro_debian9
+      Py39MitogenUbuntu1604:
+        python.version: '3.9'
+        tox.env: py39-mode_mitogen-distro_ubuntu1604
+      Py39MitogenUbuntu1804:
+        python.version: '3.9'
+        tox.env: py39-mode_mitogen-distro_ubuntu1804
+      Py39MitogenUbuntu2004:
+        python.version: '3.9'
+        tox.env: py39-mode_mitogen-distro_ubuntu2004
+      Py39Vanilla2.10:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible2.10-strategy_linear
+      Py39Vanilla3:
+        ANSIBLE_SKIP_TAGS: resource_intensive
+        python.version: '3.9'
+        tox.env: py39-mode_localhost-ansible3-strategy_linear
+      Py39Vanilla4:
+        ANSIBLE_SKIP_TAGS: resource_intensive
         python.version: '3.9'
-        tox.env: py39-mode_ansible-ansible{2.10,3,4}
+        tox.env: py39-mode_localhost-ansible4-strategy_linear

.ci/azure_matrix

@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+
+import sys
+
+import yaml
+
+def matrix():
+    for py in '2.7 3.6 3.9'.split():
+        pynodot = py.replace('.', '')
+        for mode in ['ansible', 'localhost']:
+            for ansible in '2.10 3 4'.split():
+                yield {
+                    "name": f"Py{pynodot}{mode.title()}{ansible}",
+                    "vars": {
+                        "python.version": py,
+                        "tox.env": f"py{pynodot}-mode_{mode}-ansible{ansible}",
+                    },
+                }
+                if mode in {'localhost'}:
+                    yield {
+                        "name": f"Py{pynodot}Vanilla{ansible}",
+                        "vars": {
+                            "ANSIBLE_SKIP_TAGS": "resource_intensive",
+                            "python.version": py,
+                            "tox.env": f"py{pynodot}-mode_{mode}-ansible{ansible}-strategy_linear",
+                        },
+                    }
+        for mode in ['mitogen']:
+            for distro in 'centos6,centos7,centos8,debian9,debian10,debian11,ubuntu1604,ubuntu1804,ubuntu2004'.split(','):
+                yield {
+                    "name": f"Py{pynodot}{mode.title()}{distro.title()}",
+                    "vars": {
+                        "python.version": py,
+                        "tox.env": f"py{pynodot}-mode_{mode}-distro_{distro}",
+                    },
+                }
+
+d = {x['name']: x['vars'] for x in matrix()}
+yaml.dump(d, stream=sys.stdout)

.ci/ci_lib.py

@@ -193,8 +193,6 @@ class Fold(object):
     def __exit__(self, _1, _2, _3): pass
 
 
-os.environ.setdefault('ANSIBLE_STRATEGY',
-    os.environ.get('STRATEGY', 'mitogen_linear'))
 GIT_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
 # Used only when MODE=mitogen
 DISTRO = os.environ.get('DISTRO', 'debian9')

.ci/localhost_ansible_tests.py

@@ -2,6 +2,7 @@
 # Run tests/ansible/all.yml under Ansible and Ansible-Mitogen
 
 import os
+import subprocess
 import sys
 
 import ci_lib
@@ -24,29 +25,34 @@ with ci_lib.Fold('job_setup'):
     # NOTE: sshpass v1.06 causes errors so pegging to 1.05 -> "msg": "Error when changing password","out": "passwd: DS error: eDSAuthFailed\n", 
     # there's a checksum error with "brew install http://git.io/sshpass.rb" though, so installing manually
     if not ci_lib.exists_in_path('sshpass'):
-        os.system("curl -O -L  https://sourceforge.net/projects/sshpass/files/sshpass/1.05/sshpass-1.05.tar.gz && \
+        subprocess.check_call(
+                "curl -O -L  https://sourceforge.net/projects/sshpass/files/sshpass/1.05/sshpass-1.05.tar.gz && \
                 tar xvf sshpass-1.05.tar.gz && \
                 cd sshpass-1.05 && \
                 ./configure && \
-                sudo make install")
+                sudo make install",
+                shell=True,
+        )
 
 
 with ci_lib.Fold('machine_prep'):
     # generate a new ssh key for localhost ssh
     if not os.path.exists(os.path.expanduser("~/.ssh/id_rsa")):
-        os.system("ssh-keygen -P '' -m pem -f ~/.ssh/id_rsa")
+        subprocess.check_call("ssh-keygen -P '' -m pem -f ~/.ssh/id_rsa", shell=True)
-        os.system("cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys")
+        subprocess.check_call("cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys", shell=True)
-
-    # also generate it for the sudo user
-    if os.system("sudo [ -f /var/root/.ssh/id_rsa ]") != 0:
-        os.system("sudo ssh-keygen -P '' -m pem -f /var/root/.ssh/id_rsa")
-        os.system("sudo cat /var/root/.ssh/id_rsa.pub | sudo tee -a /var/root/.ssh/authorized_keys")
-
         os.chmod(os.path.expanduser('~/.ssh'), int('0700', 8))
         os.chmod(os.path.expanduser('~/.ssh/authorized_keys'), int('0600', 8))
-    # run chmod through sudo since it's owned by root
+        #ci_lib.dump_file(os.path.expanduser('~/.ssh/authorized_keys'))
-    os.system('sudo chmod 700 /var/root/.ssh')
+        #ci_lib.dump_file('/etc/ssh/sshd_config')
-    os.system('sudo chmod 600 /var/root/.ssh/authorized_keys')
+        #subprocess.check_call('ssh -vvv -i ~/.ssh/id_rsa -o BatchMode=no -o UserKnownHostsFile=/dev/null -o PasswordAuthentication=no -o PreferredAuthentications=publickey -o IdentitiesOnly=yes -o StrictHostKeyChecking=no localhost whoami', shell=True)
+
+    # also generate it for the sudo user
+    if os.system("sudo [ -f ~root/.ssh/id_rsa ]") != 0:
+        subprocess.check_call("sudo ssh-keygen -P '' -m pem -f ~root/.ssh/id_rsa", shell=True)
+        subprocess.check_call("sudo cat ~root/.ssh/id_rsa.pub | sudo tee -a ~root/.ssh/authorized_keys", shell=True)
+        subprocess.check_call('sudo chmod 700 ~root/.ssh', shell=True)
+        subprocess.check_call('sudo chmod 600 ~root/.ssh/authorized_keys', shell=True)
+        #subprocess.check_call('sudo ssh -vvv -i ~root/.ssh/id_rsa -o BatchMode=no -o UserKnownHostsFile=/dev/null -o PasswordAuthentication=no -o PreferredAuthentications=publickey -o IdentitiesOnly=yes -o StrictHostKeyChecking=no localhost whoami', shell=True)
 
     if os.path.expanduser('~mitogen__user1') == '~mitogen__user1':
         os.chdir(IMAGE_PREP_DIR)

tests/ansible/integration/become/sudo_nonexistent.yml

@@ -25,6 +25,7 @@
             'sudo: unknown user: slartibartfast' in out.module_stdout | default(out.msg)
             or 'sudo: unknown user: slartibartfast' in out.module_stderr | default(out.msg)
             or (ansible_facts.os_family == 'RedHat' and ansible_facts.distribution_version == '6.10')
+            or 'Failed to set permissions on the temporary files Ansible needs to create when becoming an unprivileged user (rc: 1, err: chmod: Invalid file mode: A+user:slartibartfast:rx:allow\n})' in out.msg
         fail_msg: out={{out}}
       when:
         # https://github.com/ansible/ansible/pull/70785

tests/ansible/regression/issue_655__wait_for_connection_error.yml

@@ -13,36 +13,33 @@
     - name: set up test container and run tests inside it
       block:
         - name: install deps
-          block:
+          homebrew:
-            - name: install docker
+            name:
-              shell: |
+              - podman
-                # NOTE: for tracking purposes: https://github.com/docker/for-mac/issues/2359
+            state: present
-                # using docker for mac CI workaround: https://github.com/drud/ddev/pull/1748/files#diff-19288f650af2dabdf1dcc5b354d1f245
+
-                DOCKER_URL=https://download.docker.com/mac/stable/31259/Docker.dmg && 
+        - name: start machine
-                curl -O -sSL $DOCKER_URL && 
+          command:
-                open -W Docker.dmg && cp -r /Volumes/Docker/Docker.app /Applications
+            cmd: "{{ item.cmd }}"
-                sudo /Applications/Docker.app/Contents/MacOS/Docker --quit-after-install --unattended && 
+          loop:
-                ln -s /Applications/Docker.app/Contents/Resources/bin/docker /usr/local/bin/docker && 
+            - cmd: podman machine init
-                nohup /Applications/Docker.app/Contents/MacOS/Docker --unattended & 
+            - cmd: podman machine start
-                # wait 2 min for docker to come up
+            - cmd: sleep 10  # FIXME Find a way to wait until the machine is available
-                counter=0 && 
+            - cmd: podman info
-                  while ! /usr/local/bin/docker ps 2>/dev/null ; do
+          register: podman_machine
-                    if [ $counter -lt 24 ]; then
+
-                      let counter=counter+1
+        - debug:
-                    else
+            var: podman_machine
-                      exit 1
-                    fi
-                    sleep 5
-                  done
 
         # python bindings (docker_container) aren't working on this host, so gonna shell out
-        - name: create docker container
+        - name: create container
-          shell: /usr/local/bin/docker run --name testMitogen -d --rm centos:8 bash -c "sleep infinity & wait"
+          command:
+            cmd: podman run --name=testMitogen --detach --rm centos:8 bash -c "sleep infinity & wait"
 
         - name: add container to inventory
           add_host:
             name: testMitogen
-            ansible_connection: docker
+            ansible_connection: podman
             ansible_user: root
           changed_when: false
           environment:
@@ -82,6 +79,6 @@
             PATH: /usr/local/bin/:{{ ansible_env.PATH }}
 
         - name: remove test container
-          shell: /usr/local/bin/docker stop testMitogen
+          shell: podman stop testMitogen
   tags:
     - issue_655

tests/image_prep/_user_accounts.yml

@@ -108,7 +108,7 @@
       when: ansible_system == 'Linux' and out.stat.exists
       service:
         name: accounts-daemon
-        restarted: true
+        state: restarted
 
     - name: Readonly homedir for one account
       shell: "chown -R root: ~mitogen__readonly_homedir"

tests/requirements.txt

@@ -1,8 +1,8 @@
-psutil==5.4.8
 coverage==4.5.1
 Django==1.6.11  # Last version supporting 2.6.
 faulthandler==3.2; python_version < '3.3'
 mock==2.0.0
+psutil==5.8.0
 pytz==2018.5
 cffi==1.14.3  # Random pin to try and fix pyparser==2.18 not having effect
 pycparser==2.18  # Last version supporting 2.6.

tests/testlib.py

@@ -11,6 +11,7 @@ import threading
 import time
 import traceback
 
+import psutil
 import unittest2
 
 import mitogen.core
@@ -67,7 +68,6 @@ def get_fd_count():
     """
     Return the number of FDs open by this process.
     """
-    import psutil
     return psutil.Process().num_fds()
 
 
@@ -386,7 +386,8 @@ class TestCase(unittest2.TestCase):
 
         print('')
         print('Children of unit test process:')
-        os.system('ps uww --ppid ' + str(os.getpid()))
+        child_pids = ','.join(str(p.pid) for p in psutil.Process().children())
+        subprocess.check_call(['ps', '-fww', '-p', child_pids])
         assert 0, "%s leaked still-running subprocesses." % (self,)
 
     def tearDown(self):

tox.ini

@@ -65,7 +65,7 @@ deps =
     ansible3: ansible==3.4.0
     ansible4: ansible==4.8.0
 install_command =
-    python -m pip --no-python-version-warning install {opts} {packages}
+    python -mpip --no-python-version-warning --disable-pip-version-check install {opts} {packages}
 commands_pre =
     mode_ansible: {toxinidir}/.ci/ansible_install.py
     mode_debops_common: {toxinidir}/.ci/debops_common_install.py
@@ -83,6 +83,7 @@ passenv =
     AWS_SECRET_ACCESS_KEY
     HOME
 setenv =
+    ANSIBLE_STRATEGY = mitogen_linear
     NOCOVERAGE_ERASE = 1
     NOCOVERAGE_REPORT = 1
     # Only applicable to MODE=mitogen
@@ -113,7 +114,7 @@ setenv =
     mode_ansible: MODE=ansible
     mode_debops_common: MODE=debops_common
     mode_mitogen: MODE=mitogen
-    strategy_linear: STRATEGY=linear
+    strategy_linear: ANSIBLE_STRATEGY=linear
 whitelist_externals =
     docker
     docker-credential-secretservice