AsyncResult.forget() using couchdb backend throws TypeError: a bytes-like object is required, not 'str' #9864
Description
Checklist
- I have verified that the issue exists against the
mainbranch of Celery. - This has already been asked to the discussions forum first.
- 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 main branch. - I have included all related issues and possible duplicate issues
in this issue (If there are none, check this box anyway). - I have tried to reproduce the issue with pytest-celery and added the reproduction script below.
Mandatory Debugging Information
- I have included the output of
celery -A proj reportin 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
mainbranch of Celery. - I have included the contents of
pip freezein 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
- using couchdb backend throws TypeError: a bytes-like object is required, not 'str' #6781
- get result fails from couchdb in python 3 #4877
Possible Duplicates
- None
Environment & Settings
Celery version: 5.4.0 (opalescent)
celery report Output:
software -> celery:5.4.0 (opalescent) kombu:5.5.4 py:3.11.2
billiard:4.2.1 py-amqp:5.3.1
platform -> system:Linux arch:64bit, ELF
kernel version:6.1.0-37-amd64 imp:CPython
loader -> celery.loaders.app.AppLoader
settings -> transport:amqp results:couchdb://admin:**@localhost:5984/documents_tasks
broker_url: 'amqp://admin:********@localhost:5672/'
result_backend: 'couchdb://admin:********@localhost:5984/documents_tasks'
include: ['tasks']
deprecated_settings: None
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:
amqp==5.3.1
async-timeout==5.0.1
billiard==4.2.1
celery==5.4.0
certifi==2025.8.3
charset-normalizer==3.4.3
click==8.2.1
click-didyoumean==0.3.1
click-plugins==1.1.1.2
click-repl==0.3.0
idna==3.10
kombu==5.5.4
packaging==25.0
prompt_toolkit==3.0.51
pycouchdb==1.14.2
PyJWT==2.10.1
python-dateutil==2.9.0.post0
redis==5.3.1
requests==2.32.4
six==1.17.0
tzdata==2025.2
urllib3==2.5.0
vine==5.1.0
wcwidth==0.2.13
Other Dependencies
Details
N/A
Minimally Reproducible Test Case
Details
# tasks.py
from celery import Celery
app = Celery("tasks", broker=f"amqp://...", backend=f"couchdb://...")
@app.task
def add(x, y):
return x + y
# main.py
from tasks import add
promise = add.delay(6, 9)
promise.get()
promise.forget()Expected Behavior
Result is deleted from the result backend.
Actual Behavior
TypeError: a bytes-like object is required, not 'str' rises:
Details
Traceback (most recent call last):
File "/home/temax/Probe/python/celery/main.py", line 35, in <module>
promise.forget()
File "/home/temax/Probe/python/celery/.venv/lib/python3.11/site-packages/celery/result.py", line 140, in forget
self.backend.forget(self.id)
File "/home/temax/Probe/python/celery/.venv/lib/python3.11/site-packages/celery/backends/base.py", line 549, in forget
self._forget(task_id)
File "/home/temax/Probe/python/celery/.venv/lib/python3.11/site-packages/celery/backends/base.py", line 959, in _forget
self.delete(self.get_key_for_task(task_id))
File "/home/temax/Probe/python/celery/.venv/lib/python3.11/site-packages/celery/backends/couchdb.py", line 99, in delete
self.connection.delete(key)
File "/home/temax/Probe/python/celery/.venv/lib/python3.11/site-packages/pycouchdb/client.py", line 286, in delete
resource = self.resource(*_id_to_path(_id))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/temax/Probe/python/celery/.venv/lib/python3.11/site-packages/pycouchdb/resource.py", line 52, in __call__
base_url = utils.urljoin(self.base_url, *path)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/temax/Probe/python/celery/.venv/lib/python3.11/site-packages/pycouchdb/utils.py", line 86, in urljoin
return reduce(_join, path, base)
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/temax/Probe/python/celery/.venv/lib/python3.11/site-packages/pycouchdb/utils.py", line 55, in _join
parts = [head.rstrip(URLSPLITTER), tail.lstrip(URLSPLITTER)]
^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: a bytes-like object is required, not 'str'
The error is caused by this method:
celery/celery/backends/couchdb.py
Line 98 in 33eb148
Adding key = bytes_to_str(key) before self.connection.delete(key) fixes the error.