Build failing with Never call result.get() within a task

[stackexpress-shivam]

Details

• Read the Docs project URL: http://104.248.56.254:8000/projects/shivam-demo

Expected Result

The build should pass

Actual Result

Failing with following error

18/Sep/2018 09:33:52] readthedocs.core.symlink:293[10250]: INFO (Build) [shivam-demo:] Symlinking Version: Version latest of shivam-demo (20)
[18/Sep/2018 09:33:52] readthedocs.projects.tasks:1201[10250]: INFO (Build) [shivam-demo:] Updating static metadata
[18/Sep/2018 09:33:52] celery.app.trace:124[10250]: INFO Task readthedocs.projects.tasks.sync_files[7b804f09-cc03-4aa5-85eb-f56d30c7fb85] succeeded in 0.09603784999944764s: None
[18/Sep/2018 09:33:52] readthedocs.doc_builder.environments:511[10250]: ERROR (Build) [shivam-demo:latest] Never call result.get() within a task!
See http://docs.celeryq.org/en/latest/userguide/tasks.html#task-synchronous-subtasks
Traceback (most recent call last):
File "/root/s/rtd/checkouts/readthedocs.org/readthedocs/projects/tasks.py", line 507, in run_build
epub=bool(outcomes['epub']),
File "/root/s/rtd/checkouts/readthedocs.org/readthedocs/projects/tasks.py", line 645, in update_app_instances
callback=sync_callback.s(version_pk=self.version.pk, commit=self.build['commit']),
File "/root/s/rtd/checkouts/readthedocs.org/readthedocs/core/utils/init.py", line 52, in broadcast
task_promise = chord(tasks, callback).apply_async()
File "/root/s/rtd/lib/python3.6/site-packages/celery/canvas.py", line 1230, in apply_async
body=body, task_id=task_id, **options)
File "/root/s/rtd/lib/python3.6/site-packages/celery/canvas.py", line 1239, in apply
args=(tasks.apply(args, kwargs).get(propagate=propagate),),
File "/root/s/rtd/lib/python3.6/site-packages/celery/result.py", line 671, in get
on_interval=on_interval,
File "/root/s/rtd/lib/python3.6/site-packages/celery/result.py", line 722, in join
assert_will_not_block()
File "/root/s/rtd/lib/python3.6/site-packages/celery/result.py", line 41, in assert_will_not_block
raise RuntimeError(E_WOULDBLOCK)
RuntimeError: Never call result.get() within a task!
See http://docs.celeryq.org/en/latest/userguide/tasks.html#task-synchronous-subtasks

[18/Sep/2018 09:33:52] readthedocs.doc_builder.environments:621[10250]: ERROR Build failed with unhandled exception: Never call result.get() within a task!
See http://docs.celeryq.org/en/latest/userguide/tasks.html#task-synchronous-subtasks

[18/Sep/2018 09:33:52] "PUT /api/v2/build/4/ HTTP/1.1" 200 49275

[stsewd]

Thank you for filling up this issue, closing as duplicate of #4640

[stsewd]

Also, you shouldn't use rtd on debug mode in production.