Issue 1:
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,

Command: docker-compose build celery

docker_Version: Docker version 19.03.2, build 6a30dfc

docker_Compse_version: docker-compose version 1.18.0, build 8dd22a9

Error:

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>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<4.0,>=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<5.0,>=4.6.4 (from -r requirements/default.txt (line 3))
ERROR: Could not find a version that satisfies the requirement kombu<5.0,>=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<5.0,>=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 && 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 && 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 && 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 && 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

Checklist

I have read the relevant section in the

contribution guide

on reporting bugs.

I have checked the issues list

for similar or identical bug reports.

I have checked the pull requests list

for existing proposed fixes.

I have checked the commit log

to find out if the bug was already fixed in the master branch.

I have included all related issues and possible duplicate issues

in this issue (If there are none, check this box anyway).

Mandatory Debugging Information

I have included the output of celery -A proj report in the issue.

(if you are not able to do this, then at least specify the Celery

version affected).

I have verified that the issue exists against the master branch of Celery.

I have included the contents of pip freeze in the issue.

I have included all the versions of all the external dependencies required

to reproduce this bug.

Optional Debugging Information

I have tried reproducing the issue on more than one Python version

and/or implementation.

I have tried reproducing the issue on more than one message broker and/or

result backend.

I have tried reproducing the issue on more than one version of the message

broker and/or result backend.

I have tried reproducing the issue on more than one operating system.

I have tried reproducing the issue on more than one workers pool.

I have tried reproducing the issue with autoscaling, retries,

ETA/Countdown & rate limits disabled.

I have tried reproducing the issue after downgrading

and/or upgrading Celery and its dependencies.

Related Issues and Possible Duplicates

Related Issues

None

Possible Duplicates

None

Environment & Settings

Celery version:

celery report Output:

Steps to Reproduce

Required Dependencies

Minimal Python Version: N/A or Unknown

Minimal Celery Version: N/A or Unknown

Minimal Kombu Version: N/A or Unknown

Minimal Broker Version: N/A or Unknown

Minimal Result Backend Version: N/A or Unknown

Minimal OS and/or Kernel Version: N/A or Unknown

Minimal Broker Client Version: N/A or Unknown

Minimal Result Backend Client Version: N/A or Unknown

Python Packages

pip freeze Output:

Other Dependencies

N/A

Minimally Reproducible Test Case

Expected Behavior

Actual Behavior

Issue 2:
Checklist

I have read the relevant section in the

contribution guide

on reporting bugs.

I have checked the issues list

for similar or identical bug reports.

I have checked the pull requests list

for existing proposed fixes.

I have checked the commit log

to find out if the bug was already fixed in the master branch.

I have included all related issues and possible duplicate issues

in this issue (If there are none, check this box anyway).

Mandatory Debugging Information

I have included the output of celery -A proj report in the issue.

(if you are not able to do this, then at least specify the Celery

version affected).

I have verified that the issue exists against the master branch of Celery.

I have included the contents of pip freeze in the issue.

I have included all the versions of all the external dependencies required

to reproduce this bug.

Optional Debugging Information

I have tried reproducing the issue on more than one Python version

and/or implementation.

I have tried reproducing the issue on more than one message broker and/or

result backend.

I have tried reproducing the issue on more than one version of the message

broker and/or result backend.

I have tried reproducing the issue on more than one operating system.

I have tried reproducing the issue on more than one workers pool.

I have tried reproducing the issue with autoscaling, retries,

ETA/Countdown & rate limits disabled.

I have tried reproducing the issue after downgrading

and/or upgrading Celery and its dependencies.

Related Issues and Possible Duplicates

Related Issues

None

Possible Duplicates

None

Environment & Settings

Celery version: 4.4.0rc1

celery -A proj report Output:

software -> celery:4.3.0 (rhubarb) kombu:4.6.1 py:3.6.7
billiard:3.6.0.0 py-amqp:2.5.0
platform -> system:Linux arch:64bit, ELF
kernel version:4.15.0-47-generic imp:CPython
loader -> celery.loaders.app.AppLoader
settings -> 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: <bound method Settings.is_overridden of <Settings "proj.settings">>

Steps to Reproduce

Required Dependencies

Minimal Python Version: 3.6.7

Minimal Celery Version: 4.4.0rc1

Minimal Kombu Version: 4.6.1

Minimal Broker Version (RabbitMQ)(docker): 3.7.15

Minimal Result Backend Version (cassandra)(docker): 3.11.4

Minimal OS and/or Kernel Version: Linux homestead 4.15.0-47-generic #50-Ubuntu SMP Wed Mar 13 10:44:52 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Minimal Broker Client Version (amqp): 2.5.0

Minimal Result Backend Client Version(cassandra-driver): 3.18.0

Python Packages

pip freeze Output:

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

Other Dependencies

N/A

Minimally Reproducible Test Case

Follow the guide here

docker-compose.yml

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

proj/settings.py

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

proj/proj/celery.py

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()

Execute

celery worker -A pytesturu -l debug

Expected Behavior

Start worker success

Actual Behavior

Error Cassandra backend not configured

$ 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.