<p dir="auto">I am trying to build the celery docker container as mentioned in the docs to setup the dev environment. But docker build fails with below error,</p>
<p dir="auto"><strong>Command:</strong>  docker-compose build celery<br>
<strong>docker_Version:</strong> Docker version 19.03.2, build 6a30dfc<br>
<strong>docker_Compse_version:</strong> docker-compose version 1.18.0, build 8dd22a9</p>
<p dir="auto"><strong>Error:</strong></p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="    Running setup.py install for unipath: started
    Running setup.py install for unipath: finished with status 'done'
Successfully installed Jinja2-2.10.3 MarkupSafe-1.1.1 PyYAML-5.1.2 Pygments-2.4.2 Sphinx-1.8.5 alabaster-0.7.12 amqp-2.5.1 argparse-1.4.0 asn1crypto-1.0.1 aspy.yaml-1.3.0 atomicwrites-1.3.0 attrs-19.2.0 aws-xray-sdk-0.95 azure-common-1.1.5 azure-nspkg-3.0.2 azure-storage-0.36.0 azure-storage-common-1.1.0 azure-storage-nspkg-3.1.0 babel-2.7.0 basho-erlastic-2.1.1 billiard-3.6.1.0 boto-2.49.0 boto3-1.9.243 botocore-1.12.243 bumpversion-0.5.3 case-1.5.3 cassandra-driver-3.19.0 certifi-2019.9.11 cffi-1.12.3 cfgv-2.0.1 chardet-3.0.4 codecov-2.0.15 couchbase-2.5.8 coverage-4.5.4 cryptography-2.7 datetime-4.3 dnspython-1.16.0 docker-4.1.0 docutils-0.15.2 ecdsa-0.13.2 elasticsearch-7.0.5 entrypoints-0.3 ephem-3.7.7.0 eventlet-0.25.1 filelock-3.0.12 flake8-3.7.8 flakeplus-1.1.0 future-0.17.1 gevent-1.4.0 greenlet-0.4.15 identify-1.4.7 idna-2.8 imagesize-1.1.0 importlib-metadata-0.23 importlib-resources-1.0.2 jmespath-0.9.4 jsondiff-1.1.1 jsonpickle-1.2 kombu-4.6.5 linecache2-1.0.0 mccabe-0.6.1 mock-3.0.5 monotonic-1.5 more-itertools-7.2.0 moto-1.3.7 msgpack-0.6.2 nodeenv-1.3.3 nose-1.3.7 packaging-19.2 pathlib2-2.3.5 pluggy-0.13.0 pre-commit-1.18.3 py-1.8.0 pyArango-1.3.2 pyaml-19.4.1 pycodestyle-2.5.0 pycouchdb-1.14 pycparser-2.19 pycryptodome-3.9.0 pycurl-7.43.0.3 pydocstyle-1.1.1 pydocumentdb-2.3.2 pyflakes-2.1.1 pylibmc-1.6.1 pymongo-3.9.0 pyparsing-2.4.2 pytest-4.6.5 pytest-cov-2.8.0 pytest-sugar-0.9.2 pytest-travis-fold-1.3.0 python-consul-1.1.0 python-dateutil-2.8.0 python-jose-2.0.2 python-memcached-1.59 python3-protobuf-2.5.0 pytz-2019.2 redis-3.3.8 requests-2.22.0 responses-0.10.6 riak-2.7.0 s3transfer-0.2.1 simplejson-3.16.0 six-1.12.0 snowballstemmer-2.0.0 softlayer-messaging-1.0.3 sphinx-celery-1.4.6 sphinx-testing-0.7.2 sphinx2rst-1.1.0 sphinxcontrib-websupport-1.1.2 sqlalchemy-1.3.9 tblib-1.4.0 termcolor-1.1.0 toml-0.10.0 tox-3.14.0 traceback2-1.4.0 typing-3.7.4.1 unipath-1.1 unittest2-1.1.0 urllib3-1.25.6 vine-1.3.0 virtualenv-16.7.5 wcwidth-0.1.7 websocket-client-0.56.0 werkzeug-0.16.0 wheel-0.33.6 wrapt-1.11.2 xmltodict-0.12.0 zipp-0.6.0 zope.interface-4.6.0
DEPRECATION: Python 3.4 support has been deprecated. pip 19.1 will be the last one supporting it. Please upgrade your Python as Python 3.4 won't be maintained after March 2019 (cf PEP 429).
Ignoring couchbase-cffi: markers 'platform_python_implementation == &quot;PyPy&quot;' don't match your environment
Collecting pytz&gt;dev (from -r requirements/default.txt (line 1))
  Using cached https://files.pythonhosted.org/packages/87/76/46d697698a143e05f77bec5a526bf4e56a0be61d63425b68f4ba553b51f2/pytz-2019.2-py2.py3-none-any.whl
Collecting billiard&lt;4.0,&gt;=3.6.1 (from -r requirements/default.txt (line 2))
  Using cached https://files.pythonhosted.org/packages/9a/bb/2a016ac912fca48e06ff5a662407f3d1681aa47df97fb19feba7cc931ee1/billiard-3.6.1.0-py3-none-any.whl
Collecting kombu&lt;5.0,&gt;=4.6.4 (from -r requirements/default.txt (line 3))
  ERROR: Could not find a version that satisfies the requirement kombu&lt;5.0,&gt;=4.6.4 (from -r requirements/default.txt (line 3)) (from versions: 0.1.0, 0.2.0, 0.9.0, 0.9.1, 0.9.2, 0.9.4, 0.9.5, 0.9.6, 0.9.7, 1.0.0b1, 1.0.0b2, 1.0.0b3, 1.0.0b4, 1.0.0rc1, 1.0.0rc2, 1.0.0rc3, 1.0.0rc4, 1.0.0, 1.0.1, 1.0.2, 1.0.3, 1.0.4, 1.0.5, 1.0.6, 1.0.7, 1.1.0, 1.1.1, 1.1.2, 1.1.3, 1.1.4, 1.1.5, 1.1.6, 1.2.0, 1.2.1, 1.3.0, 1.3.1, 1.3.2, 1.3.3, 1.3.4, 1.3.5, 1.4.0, 1.4.1, 1.4.2, 1.4.3, 1.5.0, 1.5.1, 2.0.0, 2.1.0, 2.1.1, 2.1.2, 2.1.3, 2.1.4, 2.1.5, 2.1.6, 2.1.7, 2.1.8, 2.2.0, 2.2.1, 2.2.2, 2.2.3, 2.2.4, 2.2.5, 2.2.6, 2.3.0, 2.3.1, 2.3.2, 2.4.0, 2.4.1, 2.4.2, 2.4.3, 2.4.4, 2.4.5, 2.4.6, 2.4.7, 2.4.8, 2.4.9, 2.4.10, 2.5.0, 2.5.1, 2.5.2, 2.5.3, 2.5.4, 2.5.5, 2.5.6, 2.5.7, 2.5.8, 2.5.9, 2.5.10, 2.5.11, 2.5.12, 2.5.13, 2.5.14, 2.5.15, 2.5.16, 3.0.0, 3.0.1, 3.0.2, 3.0.3, 3.0.4, 3.0.5, 3.0.6, 3.0.7, 3.0.8, 3.0.9, 3.0.10, 3.0.11, 3.0.12, 3.0.13, 3.0.14, 3.0.15, 3.0.16, 3.0.17, 3.0.18, 3.0.19, 3.0.20, 3.0.21, 3.0.22, 3.0.23, 3.0.24, 3.0.25, 3.0.26, 3.0.27, 3.0.28, 3.0.29, 3.0.30, 3.0.31, 3.0.32, 3.0.33, 3.0.34, 3.0.35, 3.0.36, 3.0.37, 4.0.0rc3, 4.0.0rc4, 4.0.0rc5, 4.0.0rc6, 4.0.0, 4.0.1, 4.0.2, 4.1.0, 4.2.0, 4.2.1, 4.2.2.post1, 4.3.0, 4.4.0, 4.5.0)
ERROR: No matching distribution found for kombu&lt;5.0,&gt;=4.6.4 (from -r requirements/default.txt (line 3))
WARNING: You are using pip version 19.1.1, however version 19.2.3 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
ERROR: Service 'celery' failed to build: The command '/bin/sh -c pyenv exec python3.7 -m pip install   -r requirements/default.txt   -r requirements/test.txt   -r requirements/test-ci-default.txt   -r requirements/docs.txt   -r requirements/test-integration.txt   -r requirements/pkgutils.txt &amp;&amp;   pyenv exec python3.6 -m pip install   -r requirements/default.txt   -r requirements/test.txt   -r requirements/test-ci-default.txt   -r requirements/docs.txt   -r requirements/test-integration.txt   -r requirements/pkgutils.txt &amp;&amp;   pyenv exec python3.5 -m pip install   -r requirements/default.txt   -r requirements/test.txt   -r requirements/test-ci-default.txt   -r requirements/docs.txt   -r requirements/test-integration.txt   -r requirements/pkgutils.txt &amp;&amp;   pyenv exec python3.4 -m pip install   -r requirements/default.txt   -r requirements/test.txt   -r requirements/test-ci-default.txt   -r requirements/docs.txt   -r requirements/test-integration.txt   -r requirements/pkgutils.txt &amp;&amp;   pyenv exec python2.7 -m pip install   -r requirements/default.txt   -r requirements/test.txt   -r requirements/test-ci-default.txt   -r requirements/docs.txt   -r requirements/test-integration.txt   -r requirements/pkgutils.txt' returned a non-zero code: 1"><pre class="notranslate"><code class="notranslate">    Running setup.py install for unipath: started
    Running setup.py install for unipath: finished with status 'done'
Successfully installed Jinja2-2.10.3 MarkupSafe-1.1.1 PyYAML-5.1.2 Pygments-2.4.2 Sphinx-1.8.5 alabaster-0.7.12 amqp-2.5.1 argparse-1.4.0 asn1crypto-1.0.1 aspy.yaml-1.3.0 atomicwrites-1.3.0 attrs-19.2.0 aws-xray-sdk-0.95 azure-common-1.1.5 azure-nspkg-3.0.2 azure-storage-0.36.0 azure-storage-common-1.1.0 azure-storage-nspkg-3.1.0 babel-2.7.0 basho-erlastic-2.1.1 billiard-3.6.1.0 boto-2.49.0 boto3-1.9.243 botocore-1.12.243 bumpversion-0.5.3 case-1.5.3 cassandra-driver-3.19.0 certifi-2019.9.11 cffi-1.12.3 cfgv-2.0.1 chardet-3.0.4 codecov-2.0.15 couchbase-2.5.8 coverage-4.5.4 cryptography-2.7 datetime-4.3 dnspython-1.16.0 docker-4.1.0 docutils-0.15.2 ecdsa-0.13.2 elasticsearch-7.0.5 entrypoints-0.3 ephem-3.7.7.0 eventlet-0.25.1 filelock-3.0.12 flake8-3.7.8 flakeplus-1.1.0 future-0.17.1 gevent-1.4.0 greenlet-0.4.15 identify-1.4.7 idna-2.8 imagesize-1.1.0 importlib-metadata-0.23 importlib-resources-1.0.2 jmespath-0.9.4 jsondiff-1.1.1 jsonpickle-1.2 kombu-4.6.5 linecache2-1.0.0 mccabe-0.6.1 mock-3.0.5 monotonic-1.5 more-itertools-7.2.0 moto-1.3.7 msgpack-0.6.2 nodeenv-1.3.3 nose-1.3.7 packaging-19.2 pathlib2-2.3.5 pluggy-0.13.0 pre-commit-1.18.3 py-1.8.0 pyArango-1.3.2 pyaml-19.4.1 pycodestyle-2.5.0 pycouchdb-1.14 pycparser-2.19 pycryptodome-3.9.0 pycurl-7.43.0.3 pydocstyle-1.1.1 pydocumentdb-2.3.2 pyflakes-2.1.1 pylibmc-1.6.1 pymongo-3.9.0 pyparsing-2.4.2 pytest-4.6.5 pytest-cov-2.8.0 pytest-sugar-0.9.2 pytest-travis-fold-1.3.0 python-consul-1.1.0 python-dateutil-2.8.0 python-jose-2.0.2 python-memcached-1.59 python3-protobuf-2.5.0 pytz-2019.2 redis-3.3.8 requests-2.22.0 responses-0.10.6 riak-2.7.0 s3transfer-0.2.1 simplejson-3.16.0 six-1.12.0 snowballstemmer-2.0.0 softlayer-messaging-1.0.3 sphinx-celery-1.4.6 sphinx-testing-0.7.2 sphinx2rst-1.1.0 sphinxcontrib-websupport-1.1.2 sqlalchemy-1.3.9 tblib-1.4.0 termcolor-1.1.0 toml-0.10.0 tox-3.14.0 traceback2-1.4.0 typing-3.7.4.1 unipath-1.1 unittest2-1.1.0 urllib3-1.25.6 vine-1.3.0 virtualenv-16.7.5 wcwidth-0.1.7 websocket-client-0.56.0 werkzeug-0.16.0 wheel-0.33.6 wrapt-1.11.2 xmltodict-0.12.0 zipp-0.6.0 zope.interface-4.6.0
DEPRECATION: Python 3.4 support has been deprecated. pip 19.1 will be the last one supporting it. Please upgrade your Python as Python 3.4 won't be maintained after March 2019 (cf PEP 429).
Ignoring couchbase-cffi: markers 'platform_python_implementation == "PyPy"' don't match your environment
Collecting pytz&gt;dev (from -r requirements/default.txt (line 1))
  Using cached https://files.pythonhosted.org/packages/87/76/46d697698a143e05f77bec5a526bf4e56a0be61d63425b68f4ba553b51f2/pytz-2019.2-py2.py3-none-any.whl
Collecting billiard&lt;4.0,&gt;=3.6.1 (from -r requirements/default.txt (line 2))
  Using cached https://files.pythonhosted.org/packages/9a/bb/2a016ac912fca48e06ff5a662407f3d1681aa47df97fb19feba7cc931ee1/billiard-3.6.1.0-py3-none-any.whl
Collecting kombu&lt;5.0,&gt;=4.6.4 (from -r requirements/default.txt (line 3))
  ERROR: Could not find a version that satisfies the requirement kombu&lt;5.0,&gt;=4.6.4 (from -r requirements/default.txt (line 3)) (from versions: 0.1.0, 0.2.0, 0.9.0, 0.9.1, 0.9.2, 0.9.4, 0.9.5, 0.9.6, 0.9.7, 1.0.0b1, 1.0.0b2, 1.0.0b3, 1.0.0b4, 1.0.0rc1, 1.0.0rc2, 1.0.0rc3, 1.0.0rc4, 1.0.0, 1.0.1, 1.0.2, 1.0.3, 1.0.4, 1.0.5, 1.0.6, 1.0.7, 1.1.0, 1.1.1, 1.1.2, 1.1.3, 1.1.4, 1.1.5, 1.1.6, 1.2.0, 1.2.1, 1.3.0, 1.3.1, 1.3.2, 1.3.3, 1.3.4, 1.3.5, 1.4.0, 1.4.1, 1.4.2, 1.4.3, 1.5.0, 1.5.1, 2.0.0, 2.1.0, 2.1.1, 2.1.2, 2.1.3, 2.1.4, 2.1.5, 2.1.6, 2.1.7, 2.1.8, 2.2.0, 2.2.1, 2.2.2, 2.2.3, 2.2.4, 2.2.5, 2.2.6, 2.3.0, 2.3.1, 2.3.2, 2.4.0, 2.4.1, 2.4.2, 2.4.3, 2.4.4, 2.4.5, 2.4.6, 2.4.7, 2.4.8, 2.4.9, 2.4.10, 2.5.0, 2.5.1, 2.5.2, 2.5.3, 2.5.4, 2.5.5, 2.5.6, 2.5.7, 2.5.8, 2.5.9, 2.5.10, 2.5.11, 2.5.12, 2.5.13, 2.5.14, 2.5.15, 2.5.16, 3.0.0, 3.0.1, 3.0.2, 3.0.3, 3.0.4, 3.0.5, 3.0.6, 3.0.7, 3.0.8, 3.0.9, 3.0.10, 3.0.11, 3.0.12, 3.0.13, 3.0.14, 3.0.15, 3.0.16, 3.0.17, 3.0.18, 3.0.19, 3.0.20, 3.0.21, 3.0.22, 3.0.23, 3.0.24, 3.0.25, 3.0.26, 3.0.27, 3.0.28, 3.0.29, 3.0.30, 3.0.31, 3.0.32, 3.0.33, 3.0.34, 3.0.35, 3.0.36, 3.0.37, 4.0.0rc3, 4.0.0rc4, 4.0.0rc5, 4.0.0rc6, 4.0.0, 4.0.1, 4.0.2, 4.1.0, 4.2.0, 4.2.1, 4.2.2.post1, 4.3.0, 4.4.0, 4.5.0)
ERROR: No matching distribution found for kombu&lt;5.0,&gt;=4.6.4 (from -r requirements/default.txt (line 3))
WARNING: You are using pip version 19.1.1, however version 19.2.3 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
ERROR: Service 'celery' failed to build: The command '/bin/sh -c pyenv exec python3.7 -m pip install   -r requirements/default.txt   -r requirements/test.txt   -r requirements/test-ci-default.txt   -r requirements/docs.txt   -r requirements/test-integration.txt   -r requirements/pkgutils.txt &amp;&amp;   pyenv exec python3.6 -m pip install   -r requirements/default.txt   -r requirements/test.txt   -r requirements/test-ci-default.txt   -r requirements/docs.txt   -r requirements/test-integration.txt   -r requirements/pkgutils.txt &amp;&amp;   pyenv exec python3.5 -m pip install   -r requirements/default.txt   -r requirements/test.txt   -r requirements/test-ci-default.txt   -r requirements/docs.txt   -r requirements/test-integration.txt   -r requirements/pkgutils.txt &amp;&amp;   pyenv exec python3.4 -m pip install   -r requirements/default.txt   -r requirements/test.txt   -r requirements/test-ci-default.txt   -r requirements/docs.txt   -r requirements/test-integration.txt   -r requirements/pkgutils.txt &amp;&amp;   pyenv exec python2.7 -m pip install   -r requirements/default.txt   -r requirements/test.txt   -r requirements/test-ci-default.txt   -r requirements/docs.txt   -r requirements/test-integration.txt   -r requirements/pkgutils.txt' returned a non-zero code: 1
</code></pre></div>

<h1 dir="auto">Checklist</h1>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have read the relevant section in the<br>
<a href="http://docs.celeryproject.org/en/latest/contributing.html#other-bugs" rel="nofollow">contribution guide</a><br>
on reporting bugs.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/celery/celery/issues?q=is%3Aissue+label%3A%22Issue+Type%3A+Bug+Report%22+-label%3A%22Category%3A+Documentation%22">issues list</a><br>
for similar or identical bug reports.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/celery/celery/pulls?q=is%3Apr+label%3A%22PR+Type%3A+Bugfix%22+-label%3A%22Category%3A+Documentation%22">pull requests list</a><br>
for existing proposed fixes.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/celery/celery/commits/master">commit log</a><br>
to find out if the bug was already fixed in the master branch.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included all related issues and possible duplicate issues<br>
in this issue (If there are none, check this box anyway).</li>
</ul>
<h2 dir="auto">Mandatory Debugging Information</h2>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included the output of <code class="notranslate">celery -A proj report</code> in the issue.<br>
(if you are not able to do this, then at least specify the Celery<br>
version affected).</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have verified that the issue exists against the <code class="notranslate">master</code> branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included the contents of <code class="notranslate">pip freeze</code> in the issue.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included all the versions of all the external dependencies required<br>
to reproduce this bug.</li>
</ul>
<h2 dir="auto">Optional Debugging Information</h2>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one Python version<br>
and/or implementation.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one message broker and/or<br>
result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one version of the message<br>
broker and/or result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one operating system.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one workers pool.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue with autoscaling, retries,<br>
ETA/Countdown &amp; rate limits disabled.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue after downgrading<br>
and/or upgrading Celery and its dependencies.</li>
</ul>
<h2 dir="auto">Related Issues and Possible Duplicates</h2>

<h4 dir="auto">Related Issues</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h4 dir="auto">Possible Duplicates</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h2 dir="auto">Environment &amp; Settings</h2>

<p dir="auto"><strong>Celery version</strong>:</p>

<details>
<summary><b><code class="notranslate">celery report</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content=""><pre class="notranslate"><code class="notranslate"></code></pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Steps to Reproduce</h1>
<h2 dir="auto">Required Dependencies</h2>

<ul dir="auto">
<li><strong>Minimal Python Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Celery Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Kombu Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Broker Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Result Backend Version</strong>: N/A or Unknown</li>
<li><strong>Minimal OS and/or Kernel Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Broker Client Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Result Backend Client Version</strong>: N/A or Unknown</li>
</ul>
<h3 dir="auto">Python Packages</h3>

<details>
<summary><b><code class="notranslate">pip freeze</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content=""><pre class="notranslate"><code class="notranslate"></code></pre></div>
<p dir="auto"></p>
</details>
<h3 dir="auto">Other Dependencies</h3>

<details>
<p dir="auto">
N/A
</p>
</details>
<h2 dir="auto">Minimally Reproducible Test Case</h2>

<details>
<p dir="auto">
</p><div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content=""><pre class="notranslate"></pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Expected Behavior</h1>

<h1 dir="auto">Actual Behavior</h1>
<h1 dir="auto">Checklist</h1>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have read the relevant section in the<br>
<a href="http://docs.celeryproject.org/en/latest/contributing.html#other-bugs" rel="nofollow">contribution guide</a><br>
on reporting bugs.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/issues?q=is%3Aissue+label%3A%22Issue+Type%3A+Bug+Report%22+-label%3A%22Category%3A+Documentation%22">issues list</a><br>
for similar or identical bug reports.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/pulls?q=is%3Apr+label%3A%22PR+Type%3A+Bugfix%22+-label%3A%22Category%3A+Documentation%22">pull requests list</a><br>
for existing proposed fixes.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/commits/master">commit log</a><br>
to find out if the bug was already fixed in the master branch.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included all related issues and possible duplicate issues<br>
in this issue (If there are none, check this box anyway).</li>
</ul>
<h2 dir="auto">Mandatory Debugging Information</h2>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included the output of <code class="notranslate">celery -A proj report</code> in the issue.<br>
(if you are not able to do this, then at least specify the Celery<br>
version affected).</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have verified that the issue exists against the <code class="notranslate">master</code> branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included the contents of <code class="notranslate">pip freeze</code> in the issue.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included all the versions of all the external dependencies required<br>
to reproduce this bug.</li>
</ul>
<h2 dir="auto">Optional Debugging Information</h2>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one Python version<br>
and/or implementation.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one message broker and/or<br>
result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one version of the message<br>
broker and/or result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one operating system.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one workers pool.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue with autoscaling, retries,<br>
ETA/Countdown &amp; rate limits disabled.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue after downgrading<br>
and/or upgrading Celery and its dependencies.</li>
</ul>
<h2 dir="auto">Related Issues and Possible Duplicates</h2>

<h4 dir="auto">Related Issues</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h4 dir="auto">Possible Duplicates</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h2 dir="auto">Environment &amp; Settings</h2>

<p dir="auto"><strong>Celery version</strong>: 4.4.0rc1</p>

<details>
<summary><b><code class="notranslate">celery -A proj report</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="
software -&gt; celery:4.3.0 (rhubarb) kombu:4.6.1 py:3.6.7
            billiard:3.6.0.0 py-amqp:2.5.0
platform -&gt; system:Linux arch:64bit, ELF
            kernel version:4.15.0-47-generic imp:CPython
loader   -&gt; celery.loaders.app.AppLoader
settings -&gt; transport:amqp results:cassandra

ABSOLUTE_URL_OVERRIDES: {
 }
ADMINS: []
ALLOWED_HOSTS: []
APPEND_SLASH: True
AUTHENTICATION_BACKENDS: ['django.contrib.auth.backends.ModelBackend']
AUTH_PASSWORD_VALIDATORS: '********'
AUTH_USER_MODEL: 'auth.User'
BASE_DIR: '/u02/projects/proj'
CACHES: {
 'default': {'BACKEND': 'django.core.cache.backends.locmem.LocMemCache'}}
CACHE_MIDDLEWARE_ALIAS: 'default'
CACHE_MIDDLEWARE_KEY_PREFIX: '********'
CACHE_MIDDLEWARE_SECONDS: 600
CELERY_BROKER_URL: 'amqp://guest:********@localhost:5672//'
CELERY_CASSANDRA_COLUMN_FAMILY: 'tasks'
CELERY_CASSANDRA_KEYSPACE: '********'
CELERY_CASSANDRA_PORT: 9042
CELERY_CASSANDRA_SERVERS: ['localhost']
CELERY_RESULT_BACKEND: 'cassandra'
CLOUD_STORAGE_BUCKET: 'testbucket'
CSRF_COOKIE_AGE: 31449600
CSRF_COOKIE_DOMAIN: None
CSRF_COOKIE_HTTPONLY: False
CSRF_COOKIE_NAME: 'csrftoken'
CSRF_COOKIE_PATH: '/'
CSRF_COOKIE_SAMESITE: 'Lax'
CSRF_COOKIE_SECURE: False
CSRF_FAILURE_VIEW: 'django.views.csrf.csrf_failure'
CSRF_HEADER_NAME: 'HTTP_X_CSRFTOKEN'
CSRF_TRUSTED_ORIGINS: []
CSRF_USE_SESSIONS: False
DATABASES: {
    'default': {   'ATOMIC_REQUESTS': False,
                   'AUTOCOMMIT': True,
                   'CONN_MAX_AGE': 0,
                   'ENGINE': 'django.db.backends.postgresql',
                   'HOST': '127.0.0.1',
                   'NAME': 'testuru_0612',
                   'OPTIONS': {},
                   'PASSWORD': '********',
                   'PORT': '5432',
                   'TEST': {   'CHARSET': None,
                               'COLLATION': None,
                               'MIRROR': None,
                               'NAME': None},
                   'TIME_ZONE': None,
                   'USER': 'homestead'}}
DATABASE_ROUTERS: '********'
DATA_UPLOAD_MAX_MEMORY_SIZE: 2621440
DATA_UPLOAD_MAX_NUMBER_FIELDS: 1000
DATETIME_FORMAT: 'N j, Y, P'
DATETIME_INPUT_FORMATS: ['%Y-%m-%d %H:%M:%S',
 '%Y-%m-%d %H:%M:%S.%f',
 '%Y-%m-%d %H:%M',
 '%Y-%m-%d',
 '%m/%d/%Y %H:%M:%S',
 '%m/%d/%Y %H:%M:%S.%f',
 '%m/%d/%Y %H:%M',
 '%m/%d/%Y',
 '%m/%d/%y %H:%M:%S',
 '%m/%d/%y %H:%M:%S.%f',
 '%m/%d/%y %H:%M',
 '%m/%d/%y']
DATE_FORMAT: 'N j, Y'
DATE_INPUT_FORMATS: ['%Y-%m-%d',
 '%m/%d/%Y',
 '%m/%d/%y',
 '%b %d %Y',
 '%b %d, %Y',
 '%d %b %Y',
 '%d %b, %Y',
 '%B %d %Y',
 '%B %d, %Y',
 '%d %B %Y',
 '%d %B, %Y']
DEBUG: True
DEBUG_PROPAGATE_EXCEPTIONS: False
DECIMAL_SEPARATOR: '.'
DEFAULT_CHARSET: 'utf-8'
DEFAULT_CONTENT_TYPE: 'text/html'
DEFAULT_EXCEPTION_REPORTER_FILTER: 'django.views.debug.SafeExceptionReporterFilter'
DEFAULT_FILE_STORAGE: 'django.core.files.storage.FileSystemStorage'
DEFAULT_FROM_EMAIL: 'webmaster@localhost'
DEFAULT_INDEX_TABLESPACE: ''
DEFAULT_TABLESPACE: ''
DISALLOWED_USER_AGENTS: []
EMAIL_BACKEND: 'django.core.mail.backends.smtp.EmailBackend'
EMAIL_HOST: 'localhost'
EMAIL_HOST_PASSWORD: '********'
EMAIL_HOST_USER: ''
EMAIL_PORT: 25
EMAIL_SSL_CERTFILE: None
EMAIL_SSL_KEYFILE: '********'
EMAIL_SUBJECT_PREFIX: '[Django] '
EMAIL_TIMEOUT: None
EMAIL_USE_LOCALTIME: False
EMAIL_USE_SSL: False
EMAIL_USE_TLS: False
FILE_CHARSET: 'utf-8'
FILE_UPLOAD_DIRECTORY_PERMISSIONS: None
FILE_UPLOAD_HANDLERS: ['django.core.files.uploadhandler.MemoryFileUploadHandler',
 'django.core.files.uploadhandler.TemporaryFileUploadHandler']
FILE_UPLOAD_MAX_MEMORY_SIZE: 2621440
FILE_UPLOAD_PERMISSIONS: None
FILE_UPLOAD_TEMP_DIR: None
FIRST_DAY_OF_WEEK: 0
FIXTURE_DIRS: []
FORCE_SCRIPT_NAME: None
FORMAT_MODULE_PATH: None
FORM_RENDERER: 'django.forms.renderers.DjangoTemplates'
IGNORABLE_404_URLS: []
INSTALLED_APPS: ['fix_exam_question.apps.FixExamQuestionConfig',
 'geo_ip_database.apps.GeoIpDatabaseConfig',
 'django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles']
INTERNAL_IPS: []
LANGUAGES: [('af', 'Afrikaans'),
 ('ar', 'Arabic'),
 ('ast', 'Asturian'),
 ('az', 'Azerbaijani'),
 ('bg', 'Bulgarian'),
 ('be', 'Belarusian'),
 ('bn', 'Bengali'),
 ('br', 'Breton'),
 ('bs', 'Bosnian'),
 ('ca', 'Catalan'),
 ('cs', 'Czech'),
 ('cy', 'Welsh'),
 ('da', 'Danish'),
 ('de', 'German'),
 ('dsb', 'Lower Sorbian'),
 ('el', 'Greek'),
 ('en', 'English'),
 ('en-au', 'Australian English'),
 ('en-gb', 'British English'),
 ('eo', 'Esperanto'),
 ('es', 'Spanish'),
 ('es-ar', 'Argentinian Spanish'),
 ('es-co', 'Colombian Spanish'),
 ('es-mx', 'Mexican Spanish'),
 ('es-ni', 'Nicaraguan Spanish'),
 ('es-ve', 'Venezuelan Spanish'),
 ('et', 'Estonian'),
 ('eu', 'Basque'),
 ('fa', 'Persian'),
 ('fi', 'Finnish'),
 ('fr', 'French'),
 ('fy', 'Frisian'),
 ('ga', 'Irish'),
 ('gd', 'Scottish Gaelic'),
 ('gl', 'Galician'),
 ('he', 'Hebrew'),
 ('hi', 'Hindi'),
 ('hr', 'Croatian'),
 ('hsb', 'Upper Sorbian'),
 ('hu', 'Hungarian'),
 ('hy', 'Armenian'),
 ('ia', 'Interlingua'),
 ('id', 'Indonesian'),
 ('io', 'Ido'),
 ('is', 'Icelandic'),
 ('it', 'Italian'),
 ('ja', 'Japanese'),
 ('ka', 'Georgian'),
 ('kab', 'Kabyle'),
 ('kk', 'Kazakh'),
 ('km', 'Khmer'),
 ('kn', 'Kannada'),
 ('ko', 'Korean'),
 ('lb', 'Luxembourgish'),
 ('lt', 'Lithuanian'),
 ('lv', 'Latvian'),
 ('mk', 'Macedonian'),
 ('ml', 'Malayalam'),
 ('mn', 'Mongolian'),
 ('mr', 'Marathi'),
 ('my', 'Burmese'),
 ('nb', 'Norwegian Bokmål'),
 ('ne', 'Nepali'),
 ('nl', 'Dutch'),
 ('nn', 'Norwegian Nynorsk'),
 ('os', 'Ossetic'),
 ('pa', 'Punjabi'),
 ('pl', 'Polish'),
 ('pt', 'Portuguese'),
 ('pt-br', 'Brazilian Portuguese'),
 ('ro', 'Romanian'),
 ('ru', 'Russian'),
 ('sk', 'Slovak'),
 ('sl', 'Slovenian'),
 ('sq', 'Albanian'),
 ('sr', 'Serbian'),
 ('sr-latn', 'Serbian Latin'),
 ('sv', 'Swedish'),
 ('sw', 'Swahili'),
 ('ta', 'Tamil'),
 ('te', 'Telugu'),
 ('th', 'Thai'),
 ('tr', 'Turkish'),
 ('tt', 'Tatar'),
 ('udm', 'Udmurt'),
 ('uk', 'Ukrainian'),
 ('ur', 'Urdu'),
 ('vi', 'Vietnamese'),
 ('zh-hans', 'Simplified Chinese'),
 ('zh-hant', 'Traditional Chinese')]
LANGUAGES_BIDI: ['he', 'ar', 'fa', 'ur']
LANGUAGE_CODE: 'en-us'
LANGUAGE_COOKIE_AGE: None
LANGUAGE_COOKIE_DOMAIN: None
LANGUAGE_COOKIE_NAME: 'django_language'
LANGUAGE_COOKIE_PATH: '/'
LOCALE_PATHS: []
LOGGING: {
    'disable_existing_loggers': False,
    'formatters': {   'simple': {   'format': '{levelname} {asctime} {module} '
                                              '{message}',
                                    'style': '{'},
                      'verbose': {   'format': '{levelname} {asctime} {module} '
                                               '{process:d} {thread:d} '
                                               '{message}',
                                     'style': '{'}},
    'handlers': {   'console': {'class': 'logging.StreamHandler'},},
    'version': 1}
LOGGING_CONFIG: 'logging.config.dictConfig'
LOGIN_REDIRECT_URL: '/accounts/profile/'
LOGIN_URL: '/accounts/login/'
LOGOUT_REDIRECT_URL: None
MANAGERS: []
MEDIA_ROOT: ''
MEDIA_URL: ''
MESSAGE_STORAGE: 'django.contrib.messages.storage.fallback.FallbackStorage'
MIDDLEWARE: ['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']
MIGRATION_MODULES: {
 }
MONTH_DAY_FORMAT: 'F j'
NUMBER_GROUPING: 0
PASSWORD_HASHERS: '********'
PASSWORD_RESET_TIMEOUT_DAYS: '********'
PREPEND_WWW: False
RESOURCE_DIRECTORY: '/u02/share/tmp/proj'
ROOT_URLCONF: 'proj.urls'
SECRET_KEY: '********'
SECURE_BROWSER_XSS_FILTER: False
SECURE_CONTENT_TYPE_NOSNIFF: False
SECURE_HSTS_INCLUDE_SUBDOMAINS: False
SECURE_HSTS_PRELOAD: False
SECURE_HSTS_SECONDS: 0
SECURE_PROXY_SSL_HEADER: None
SECURE_REDIRECT_EXEMPT: []
SECURE_SSL_HOST: None
SECURE_SSL_REDIRECT: False
SERVER_EMAIL: 'root@localhost'
SESSION_CACHE_ALIAS: 'default'
SESSION_COOKIE_AGE: 1209600
SESSION_COOKIE_DOMAIN: None
SESSION_COOKIE_HTTPONLY: True
SESSION_COOKIE_NAME: 'sessionid'
SESSION_COOKIE_PATH: '/'
SESSION_COOKIE_SAMESITE: 'Lax'
SESSION_COOKIE_SECURE: False
SESSION_ENGINE: 'django.contrib.sessions.backends.db'
SESSION_EXPIRE_AT_BROWSER_CLOSE: False
SESSION_FILE_PATH: None
SESSION_SAVE_EVERY_REQUEST: False
SESSION_SERIALIZER: 'django.contrib.sessions.serializers.JSONSerializer'
SETTINGS_MODULE: 'proj.settings'
SHORT_DATETIME_FORMAT: 'm/d/Y P'
SHORT_DATE_FORMAT: 'm/d/Y'
SIGNING_BACKEND: 'django.core.signing.TimestampSigner'
SILENCED_SYSTEM_CHECKS: []
STATICFILES_DIRS: []
STATICFILES_FINDERS: ['django.contrib.staticfiles.finders.FileSystemFinder',
 'django.contrib.staticfiles.finders.AppDirectoriesFinder']
STATICFILES_STORAGE: 'django.contrib.staticfiles.storage.StaticFilesStorage'
STATIC_ROOT: None
STATIC_URL: '/static/'
TEMPLATES: [{'APP_DIRS': True,
  'BACKEND': 'django.template.backends.django.DjangoTemplates',
  'DIRS': [],
  'OPTIONS': {'context_processors': ['django.template.context_processors.debug',
                                     'django.template.context_processors.request',
                                     'django.contrib.auth.context_processors.auth',
                                     'django.contrib.messages.context_processors.messages']}}]
TEMP_DIRECTORY: '/u02/share/tmp/proj/tmp'
TEST_NON_SERIALIZED_APPS: []
TEST_RUNNER: 'django.test.runner.DiscoverRunner'
THOUSAND_SEPARATOR: ','
TIME_FORMAT: 'P'
TIME_INPUT_FORMATS: ['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']
TIME_ZONE: 'UTC'
USE_I18N: True
USE_L10N: True
USE_THOUSAND_SEPARATOR: False
USE_TZ: True
USE_X_FORWARDED_HOST: False
USE_X_FORWARDED_PORT: False
WSGI_APPLICATION: 'proj.wsgi.application'
X_FRAME_OPTIONS: 'SAMEORIGIN'
YEAR_MONTH_FORMAT: 'F Y'
is_overridden: &lt;bound method Settings.is_overridden of &lt;Settings &quot;proj.settings&quot;&gt;&gt;"><pre class="notranslate"><code class="notranslate">
software -&gt; celery:4.3.0 (rhubarb) kombu:4.6.1 py:3.6.7
            billiard:3.6.0.0 py-amqp:2.5.0
platform -&gt; system:Linux arch:64bit, ELF
            kernel version:4.15.0-47-generic imp:CPython
loader   -&gt; celery.loaders.app.AppLoader
settings -&gt; transport:amqp results:cassandra

ABSOLUTE_URL_OVERRIDES: {
 }
ADMINS: []
ALLOWED_HOSTS: []
APPEND_SLASH: True
AUTHENTICATION_BACKENDS: ['django.contrib.auth.backends.ModelBackend']
AUTH_PASSWORD_VALIDATORS: '********'
AUTH_USER_MODEL: 'auth.User'
BASE_DIR: '/u02/projects/proj'
CACHES: {
 'default': {'BACKEND': 'django.core.cache.backends.locmem.LocMemCache'}}
CACHE_MIDDLEWARE_ALIAS: 'default'
CACHE_MIDDLEWARE_KEY_PREFIX: '********'
CACHE_MIDDLEWARE_SECONDS: 600
CELERY_BROKER_URL: 'amqp://guest:********@localhost:5672//'
CELERY_CASSANDRA_COLUMN_FAMILY: 'tasks'
CELERY_CASSANDRA_KEYSPACE: '********'
CELERY_CASSANDRA_PORT: 9042
CELERY_CASSANDRA_SERVERS: ['localhost']
CELERY_RESULT_BACKEND: 'cassandra'
CLOUD_STORAGE_BUCKET: 'testbucket'
CSRF_COOKIE_AGE: 31449600
CSRF_COOKIE_DOMAIN: None
CSRF_COOKIE_HTTPONLY: False
CSRF_COOKIE_NAME: 'csrftoken'
CSRF_COOKIE_PATH: '/'
CSRF_COOKIE_SAMESITE: 'Lax'
CSRF_COOKIE_SECURE: False
CSRF_FAILURE_VIEW: 'django.views.csrf.csrf_failure'
CSRF_HEADER_NAME: 'HTTP_X_CSRFTOKEN'
CSRF_TRUSTED_ORIGINS: []
CSRF_USE_SESSIONS: False
DATABASES: {
    'default': {   'ATOMIC_REQUESTS': False,
                   'AUTOCOMMIT': True,
                   'CONN_MAX_AGE': 0,
                   'ENGINE': 'django.db.backends.postgresql',
                   'HOST': '127.0.0.1',
                   'NAME': 'testuru_0612',
                   'OPTIONS': {},
                   'PASSWORD': '********',
                   'PORT': '5432',
                   'TEST': {   'CHARSET': None,
                               'COLLATION': None,
                               'MIRROR': None,
                               'NAME': None},
                   'TIME_ZONE': None,
                   'USER': 'homestead'}}
DATABASE_ROUTERS: '********'
DATA_UPLOAD_MAX_MEMORY_SIZE: 2621440
DATA_UPLOAD_MAX_NUMBER_FIELDS: 1000
DATETIME_FORMAT: 'N j, Y, P'
DATETIME_INPUT_FORMATS: ['%Y-%m-%d %H:%M:%S',
 '%Y-%m-%d %H:%M:%S.%f',
 '%Y-%m-%d %H:%M',
 '%Y-%m-%d',
 '%m/%d/%Y %H:%M:%S',
 '%m/%d/%Y %H:%M:%S.%f',
 '%m/%d/%Y %H:%M',
 '%m/%d/%Y',
 '%m/%d/%y %H:%M:%S',
 '%m/%d/%y %H:%M:%S.%f',
 '%m/%d/%y %H:%M',
 '%m/%d/%y']
DATE_FORMAT: 'N j, Y'
DATE_INPUT_FORMATS: ['%Y-%m-%d',
 '%m/%d/%Y',
 '%m/%d/%y',
 '%b %d %Y',
 '%b %d, %Y',
 '%d %b %Y',
 '%d %b, %Y',
 '%B %d %Y',
 '%B %d, %Y',
 '%d %B %Y',
 '%d %B, %Y']
DEBUG: True
DEBUG_PROPAGATE_EXCEPTIONS: False
DECIMAL_SEPARATOR: '.'
DEFAULT_CHARSET: 'utf-8'
DEFAULT_CONTENT_TYPE: 'text/html'
DEFAULT_EXCEPTION_REPORTER_FILTER: 'django.views.debug.SafeExceptionReporterFilter'
DEFAULT_FILE_STORAGE: 'django.core.files.storage.FileSystemStorage'
DEFAULT_FROM_EMAIL: 'webmaster@localhost'
DEFAULT_INDEX_TABLESPACE: ''
DEFAULT_TABLESPACE: ''
DISALLOWED_USER_AGENTS: []
EMAIL_BACKEND: 'django.core.mail.backends.smtp.EmailBackend'
EMAIL_HOST: 'localhost'
EMAIL_HOST_PASSWORD: '********'
EMAIL_HOST_USER: ''
EMAIL_PORT: 25
EMAIL_SSL_CERTFILE: None
EMAIL_SSL_KEYFILE: '********'
EMAIL_SUBJECT_PREFIX: '[Django] '
EMAIL_TIMEOUT: None
EMAIL_USE_LOCALTIME: False
EMAIL_USE_SSL: False
EMAIL_USE_TLS: False
FILE_CHARSET: 'utf-8'
FILE_UPLOAD_DIRECTORY_PERMISSIONS: None
FILE_UPLOAD_HANDLERS: ['django.core.files.uploadhandler.MemoryFileUploadHandler',
 'django.core.files.uploadhandler.TemporaryFileUploadHandler']
FILE_UPLOAD_MAX_MEMORY_SIZE: 2621440
FILE_UPLOAD_PERMISSIONS: None
FILE_UPLOAD_TEMP_DIR: None
FIRST_DAY_OF_WEEK: 0
FIXTURE_DIRS: []
FORCE_SCRIPT_NAME: None
FORMAT_MODULE_PATH: None
FORM_RENDERER: 'django.forms.renderers.DjangoTemplates'
IGNORABLE_404_URLS: []
INSTALLED_APPS: ['fix_exam_question.apps.FixExamQuestionConfig',
 'geo_ip_database.apps.GeoIpDatabaseConfig',
 'django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles']
INTERNAL_IPS: []
LANGUAGES: [('af', 'Afrikaans'),
 ('ar', 'Arabic'),
 ('ast', 'Asturian'),
 ('az', 'Azerbaijani'),
 ('bg', 'Bulgarian'),
 ('be', 'Belarusian'),
 ('bn', 'Bengali'),
 ('br', 'Breton'),
 ('bs', 'Bosnian'),
 ('ca', 'Catalan'),
 ('cs', 'Czech'),
 ('cy', 'Welsh'),
 ('da', 'Danish'),
 ('de', 'German'),
 ('dsb', 'Lower Sorbian'),
 ('el', 'Greek'),
 ('en', 'English'),
 ('en-au', 'Australian English'),
 ('en-gb', 'British English'),
 ('eo', 'Esperanto'),
 ('es', 'Spanish'),
 ('es-ar', 'Argentinian Spanish'),
 ('es-co', 'Colombian Spanish'),
 ('es-mx', 'Mexican Spanish'),
 ('es-ni', 'Nicaraguan Spanish'),
 ('es-ve', 'Venezuelan Spanish'),
 ('et', 'Estonian'),
 ('eu', 'Basque'),
 ('fa', 'Persian'),
 ('fi', 'Finnish'),
 ('fr', 'French'),
 ('fy', 'Frisian'),
 ('ga', 'Irish'),
 ('gd', 'Scottish Gaelic'),
 ('gl', 'Galician'),
 ('he', 'Hebrew'),
 ('hi', 'Hindi'),
 ('hr', 'Croatian'),
 ('hsb', 'Upper Sorbian'),
 ('hu', 'Hungarian'),
 ('hy', 'Armenian'),
 ('ia', 'Interlingua'),
 ('id', 'Indonesian'),
 ('io', 'Ido'),
 ('is', 'Icelandic'),
 ('it', 'Italian'),
 ('ja', 'Japanese'),
 ('ka', 'Georgian'),
 ('kab', 'Kabyle'),
 ('kk', 'Kazakh'),
 ('km', 'Khmer'),
 ('kn', 'Kannada'),
 ('ko', 'Korean'),
 ('lb', 'Luxembourgish'),
 ('lt', 'Lithuanian'),
 ('lv', 'Latvian'),
 ('mk', 'Macedonian'),
 ('ml', 'Malayalam'),
 ('mn', 'Mongolian'),
 ('mr', 'Marathi'),
 ('my', 'Burmese'),
 ('nb', 'Norwegian Bokmål'),
 ('ne', 'Nepali'),
 ('nl', 'Dutch'),
 ('nn', 'Norwegian Nynorsk'),
 ('os', 'Ossetic'),
 ('pa', 'Punjabi'),
 ('pl', 'Polish'),
 ('pt', 'Portuguese'),
 ('pt-br', 'Brazilian Portuguese'),
 ('ro', 'Romanian'),
 ('ru', 'Russian'),
 ('sk', 'Slovak'),
 ('sl', 'Slovenian'),
 ('sq', 'Albanian'),
 ('sr', 'Serbian'),
 ('sr-latn', 'Serbian Latin'),
 ('sv', 'Swedish'),
 ('sw', 'Swahili'),
 ('ta', 'Tamil'),
 ('te', 'Telugu'),
 ('th', 'Thai'),
 ('tr', 'Turkish'),
 ('tt', 'Tatar'),
 ('udm', 'Udmurt'),
 ('uk', 'Ukrainian'),
 ('ur', 'Urdu'),
 ('vi', 'Vietnamese'),
 ('zh-hans', 'Simplified Chinese'),
 ('zh-hant', 'Traditional Chinese')]
LANGUAGES_BIDI: ['he', 'ar', 'fa', 'ur']
LANGUAGE_CODE: 'en-us'
LANGUAGE_COOKIE_AGE: None
LANGUAGE_COOKIE_DOMAIN: None
LANGUAGE_COOKIE_NAME: 'django_language'
LANGUAGE_COOKIE_PATH: '/'
LOCALE_PATHS: []
LOGGING: {
    'disable_existing_loggers': False,
    'formatters': {   'simple': {   'format': '{levelname} {asctime} {module} '
                                              '{message}',
                                    'style': '{'},
                      'verbose': {   'format': '{levelname} {asctime} {module} '
                                               '{process:d} {thread:d} '
                                               '{message}',
                                     'style': '{'}},
    'handlers': {   'console': {'class': 'logging.StreamHandler'},},
    'version': 1}
LOGGING_CONFIG: 'logging.config.dictConfig'
LOGIN_REDIRECT_URL: '/accounts/profile/'
LOGIN_URL: '/accounts/login/'
LOGOUT_REDIRECT_URL: None
MANAGERS: []
MEDIA_ROOT: ''
MEDIA_URL: ''
MESSAGE_STORAGE: 'django.contrib.messages.storage.fallback.FallbackStorage'
MIDDLEWARE: ['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']
MIGRATION_MODULES: {
 }
MONTH_DAY_FORMAT: 'F j'
NUMBER_GROUPING: 0
PASSWORD_HASHERS: '********'
PASSWORD_RESET_TIMEOUT_DAYS: '********'
PREPEND_WWW: False
RESOURCE_DIRECTORY: '/u02/share/tmp/proj'
ROOT_URLCONF: 'proj.urls'
SECRET_KEY: '********'
SECURE_BROWSER_XSS_FILTER: False
SECURE_CONTENT_TYPE_NOSNIFF: False
SECURE_HSTS_INCLUDE_SUBDOMAINS: False
SECURE_HSTS_PRELOAD: False
SECURE_HSTS_SECONDS: 0
SECURE_PROXY_SSL_HEADER: None
SECURE_REDIRECT_EXEMPT: []
SECURE_SSL_HOST: None
SECURE_SSL_REDIRECT: False
SERVER_EMAIL: 'root@localhost'
SESSION_CACHE_ALIAS: 'default'
SESSION_COOKIE_AGE: 1209600
SESSION_COOKIE_DOMAIN: None
SESSION_COOKIE_HTTPONLY: True
SESSION_COOKIE_NAME: 'sessionid'
SESSION_COOKIE_PATH: '/'
SESSION_COOKIE_SAMESITE: 'Lax'
SESSION_COOKIE_SECURE: False
SESSION_ENGINE: 'django.contrib.sessions.backends.db'
SESSION_EXPIRE_AT_BROWSER_CLOSE: False
SESSION_FILE_PATH: None
SESSION_SAVE_EVERY_REQUEST: False
SESSION_SERIALIZER: 'django.contrib.sessions.serializers.JSONSerializer'
SETTINGS_MODULE: 'proj.settings'
SHORT_DATETIME_FORMAT: 'm/d/Y P'
SHORT_DATE_FORMAT: 'm/d/Y'
SIGNING_BACKEND: 'django.core.signing.TimestampSigner'
SILENCED_SYSTEM_CHECKS: []
STATICFILES_DIRS: []
STATICFILES_FINDERS: ['django.contrib.staticfiles.finders.FileSystemFinder',
 'django.contrib.staticfiles.finders.AppDirectoriesFinder']
STATICFILES_STORAGE: 'django.contrib.staticfiles.storage.StaticFilesStorage'
STATIC_ROOT: None
STATIC_URL: '/static/'
TEMPLATES: [{'APP_DIRS': True,
  'BACKEND': 'django.template.backends.django.DjangoTemplates',
  'DIRS': [],
  'OPTIONS': {'context_processors': ['django.template.context_processors.debug',
                                     'django.template.context_processors.request',
                                     'django.contrib.auth.context_processors.auth',
                                     'django.contrib.messages.context_processors.messages']}}]
TEMP_DIRECTORY: '/u02/share/tmp/proj/tmp'
TEST_NON_SERIALIZED_APPS: []
TEST_RUNNER: 'django.test.runner.DiscoverRunner'
THOUSAND_SEPARATOR: ','
TIME_FORMAT: 'P'
TIME_INPUT_FORMATS: ['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']
TIME_ZONE: 'UTC'
USE_I18N: True
USE_L10N: True
USE_THOUSAND_SEPARATOR: False
USE_TZ: True
USE_X_FORWARDED_HOST: False
USE_X_FORWARDED_PORT: False
WSGI_APPLICATION: 'proj.wsgi.application'
X_FRAME_OPTIONS: 'SAMEORIGIN'
YEAR_MONTH_FORMAT: 'F Y'
is_overridden: &lt;bound method Settings.is_overridden of &lt;Settings "proj.settings"&gt;&gt;
</code></pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Steps to Reproduce</h1>
<h2 dir="auto">Required Dependencies</h2>

<ul dir="auto">
<li><strong>Minimal Python Version</strong>: 3.6.7</li>
<li><strong>Minimal Celery Version</strong>: 4.4.0rc1</li>
<li><strong>Minimal Kombu Version</strong>: 4.6.1</li>
<li><strong>Minimal Broker Version (RabbitMQ)(docker)</strong>: 3.7.15</li>
<li><strong>Minimal Result Backend Version (cassandra)(docker)</strong>: 3.11.4</li>
<li><strong>Minimal OS and/or Kernel Version</strong>: Linux homestead 4.15.0-47-generic <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="88843" data-permission-text="Title is private" data-url="https://github.com/celery/celery/issues/50" data-hovercard-type="issue" data-hovercard-url="/celery/celery/issues/50/hovercard" href="https://github.com/celery/celery/issues/50">#50</a>-Ubuntu SMP Wed Mar 13 10:44:52 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux</li>
<li><strong>Minimal Broker Client Version (amqp)</strong>: 2.5.0</li>
<li><strong>Minimal Result Backend Client Version(cassandra-driver)</strong>: 3.18.0</li>
</ul>
<h3 dir="auto">Python Packages</h3>

<details>
<summary><b><code class="notranslate">pip freeze</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="amqp==2.5.0
Babel==2.7.0
billiard==3.6.0.0
cassandra-driver==3.18.0
celery==4.4.0rc1
Django==2.2.2
kombu==4.6.1
psycopg2-binary==2.8.2
PyPDF2==1.26.0
python-decouple==3.1
pytz==2019.1
six==1.12.0
sqlparse==0.3.0
tornado==6.0.2
vine==1.3.0
Wand==0.5.4"><pre class="notranslate"><code class="notranslate">amqp==2.5.0
Babel==2.7.0
billiard==3.6.0.0
cassandra-driver==3.18.0
celery==4.4.0rc1
Django==2.2.2
kombu==4.6.1
psycopg2-binary==2.8.2
PyPDF2==1.26.0
python-decouple==3.1
pytz==2019.1
six==1.12.0
sqlparse==0.3.0
tornado==6.0.2
vine==1.3.0
Wand==0.5.4
</code></pre></div>
<p dir="auto"></p>
</details>
<h3 dir="auto">Other Dependencies</h3>

<details>
<p dir="auto">
N/A
</p>
</details>
<h2 dir="auto">Minimally Reproducible Test Case</h2>

<p dir="auto">Follow the guide <a href="http://docs.celeryproject.org/en/latest/django/first-steps-with-django.html#django-first-steps" rel="nofollow">here</a></p>
<details>
<p dir="auto">
docker-compose.yml
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="version: &quot;3&quot;
services:
  rabbitmq:
    image: rabbitmq
    restart: always
    ports:
      - 5462:5462
      - 5671-5672:5671-5672
  cassandra:
    image: cassandra
    restart: always
    ports:
      - 7000:7000
      - 9042:9042"><pre class="notranslate"><code class="notranslate">version: "3"
services:
  rabbitmq:
    image: rabbitmq
    restart: always
    ports:
      - 5462:5462
      - 5671-5672:5671-5672
  cassandra:
    image: cassandra
    restart: always
    ports:
      - 7000:7000
      - 9042:9042
</code></pre></div>
<p dir="auto">proj/settings.py</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="CELERY_BROKER_URL = 'amqp://localhost'
CELERY_RESULT_BACKEND = 'cassandra'
CELERY_CASSANDRA_SERVERS = ['localhost']
CELERY_CASSANDRA_COLUMN_FAMILY = 'tasks'
CELERY_CASSANDRA_KEYSPACE = 'celery'
CELERY_CASSANDRA_PORT = 9042"><pre class="notranslate"><code class="notranslate">CELERY_BROKER_URL = 'amqp://localhost'
CELERY_RESULT_BACKEND = 'cassandra'
CELERY_CASSANDRA_SERVERS = ['localhost']
CELERY_CASSANDRA_COLUMN_FAMILY = 'tasks'
CELERY_CASSANDRA_KEYSPACE = 'celery'
CELERY_CASSANDRA_PORT = 9042
</code></pre></div>
<p dir="auto">proj/proj/celery.py</p>
<div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="from __future__ import absolute_import, unicode_literals
import os
from celery import Celery

# set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'pytesturu.settings')

app = Celery('proj')

# Using a string here means the worker doesn't have to serialize
# the configuration object to child processes.
# - namespace='CELERY' means all celery-related configuration keys
#   should have a `CELERY_` prefix.
app.config_from_object('django.conf:settings', namespace='CELERY')

# Load task modules from all registered Django app configs.
app.autodiscover_tasks()"><pre class="notranslate"><span class="pl-k">from</span> __future__ <span class="pl-k">import</span> <span class="pl-s1">absolute_import</span>, <span class="pl-s1">unicode_literals</span>
<span class="pl-k">import</span> <span class="pl-s1">os</span>
<span class="pl-k">from</span> <span class="pl-s1">celery</span> <span class="pl-k">import</span> <span class="pl-v">Celery</span>

<span class="pl-c"># set the default Django settings module for the 'celery' program.</span>
<span class="pl-s1">os</span>.<span class="pl-s1">environ</span>.<span class="pl-en">setdefault</span>(<span class="pl-s">'DJANGO_SETTINGS_MODULE'</span>, <span class="pl-s">'pytesturu.settings'</span>)

<span class="pl-s1">app</span> <span class="pl-c1">=</span> <span class="pl-v">Celery</span>(<span class="pl-s">'proj'</span>)

<span class="pl-c"># Using a string here means the worker doesn't have to serialize</span>
<span class="pl-c"># the configuration object to child processes.</span>
<span class="pl-c"># - namespace='CELERY' means all celery-related configuration keys</span>
<span class="pl-c">#   should have a `CELERY_` prefix.</span>
<span class="pl-s1">app</span>.<span class="pl-en">config_from_object</span>(<span class="pl-s">'django.conf:settings'</span>, <span class="pl-s1">namespace</span><span class="pl-c1">=</span><span class="pl-s">'CELERY'</span>)

<span class="pl-c"># Load task modules from all registered Django app configs.</span>
<span class="pl-s1">app</span>.<span class="pl-en">autodiscover_tasks</span>()</pre></div>
<p dir="auto">Execute</p>
<div class="highlight highlight-source-shell notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="celery worker -A pytesturu -l debug"><pre class="notranslate">celery worker -A pytesturu -l debug</pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Expected Behavior</h1>

<p dir="auto">Start worker success</p>
<h1 dir="auto">Actual Behavior</h1>

<p dir="auto">Error <code class="notranslate">Cassandra backend not configured</code></p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="$ celery worker -A proj -l debug
[2019-06-13 04:12:19,786: DEBUG/MainProcess] | Worker: Preparing bootsteps.
[2019-06-13 04:12:19,789: DEBUG/MainProcess] | Worker: Building graph...
[2019-06-13 04:12:19,789: DEBUG/MainProcess] | Worker: New boot order: {Timer, Hub, Pool, Autoscaler, Beat, StateDB, Consumer}
[2019-06-13 04:12:19,804: DEBUG/MainProcess] | Consumer: Preparing bootsteps.
[2019-06-13 04:12:19,804: DEBUG/MainProcess] | Consumer: Building graph...
[2019-06-13 04:12:19,817: DEBUG/MainProcess] | Consumer: New boot order: {Connection, Agent, Events, Mingle, Tasks, Control, Gossip, Heart, event loop}
[2019-06-13 04:12:19,912: CRITICAL/MainProcess] Unrecoverable error: ImproperlyConfigured('Cassandra backend not configured.',)
Traceback (most recent call last):
  File &quot;/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/kombu/utils/objects.py&quot;, line 42, in __get__
    return obj.__dict__[self.__name__]
KeyError: 'backend'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File &quot;/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/worker/worker.py&quot;, line 205, in start
    self.blueprint.start(self)
  File &quot;/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/bootsteps.py&quot;, line 115, in start
    self.on_start()
  File &quot;/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/apps/worker.py&quot;, line 139, in on_start
    self.emit_banner()
  File &quot;/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/apps/worker.py&quot;, line 154, in emit_banner
    ' \n', self.startup_info(artlines=not use_image))),
  File &quot;/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/apps/worker.py&quot;, line 217, in startup_info
    results=self.app.backend.as_uri(),
  File &quot;/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/kombu/utils/objects.py&quot;, line 44, in __get__
    value = obj.__dict__[self.__name__] = self.__get(obj)
  File &quot;/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/app/base.py&quot;, line 1209, in backend
    return self._get_backend()
  File &quot;/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/app/base.py&quot;, line 928, in _get_backend
    return backend(app=self, url=url)
  File &quot;/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/backends/cassandra.py&quot;, line 100, in __init__
    raise ImproperlyConfigured('Cassandra backend not configured.')
celery.exceptions.ImproperlyConfigured: Cassandra backend not configured."><pre class="notranslate"><code class="notranslate">$ celery worker -A proj -l debug
[2019-06-13 04:12:19,786: DEBUG/MainProcess] | Worker: Preparing bootsteps.
[2019-06-13 04:12:19,789: DEBUG/MainProcess] | Worker: Building graph...
[2019-06-13 04:12:19,789: DEBUG/MainProcess] | Worker: New boot order: {Timer, Hub, Pool, Autoscaler, Beat, StateDB, Consumer}
[2019-06-13 04:12:19,804: DEBUG/MainProcess] | Consumer: Preparing bootsteps.
[2019-06-13 04:12:19,804: DEBUG/MainProcess] | Consumer: Building graph...
[2019-06-13 04:12:19,817: DEBUG/MainProcess] | Consumer: New boot order: {Connection, Agent, Events, Mingle, Tasks, Control, Gossip, Heart, event loop}
[2019-06-13 04:12:19,912: CRITICAL/MainProcess] Unrecoverable error: ImproperlyConfigured('Cassandra backend not configured.',)
Traceback (most recent call last):
  File "/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/kombu/utils/objects.py", line 42, in __get__
    return obj.__dict__[self.__name__]
KeyError: 'backend'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/worker/worker.py", line 205, in start
    self.blueprint.start(self)
  File "/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/bootsteps.py", line 115, in start
    self.on_start()
  File "/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/apps/worker.py", line 139, in on_start
    self.emit_banner()
  File "/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/apps/worker.py", line 154, in emit_banner
    ' \n', self.startup_info(artlines=not use_image))),
  File "/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/apps/worker.py", line 217, in startup_info
    results=self.app.backend.as_uri(),
  File "/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/kombu/utils/objects.py", line 44, in __get__
    value = obj.__dict__[self.__name__] = self.__get(obj)
  File "/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/app/base.py", line 1209, in backend
    return self._get_backend()
  File "/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/app/base.py", line 928, in _get_backend
    return backend(app=self, url=url)
  File "/home/vagrant/.virtualenvs/testuru/lib/python3.6/site-packages/celery/backends/cassandra.py", line 100, in __init__
    raise ImproperlyConfigured('Cassandra backend not configured.')
celery.exceptions.ImproperlyConfigured: Cassandra backend not configured.
</code></pre></div>