Pulp

Consider this diff applied onto a sync task in core:

[bmbouter@localhost pulp]$ git diff platform/pulpcore/app/tasks/importer.py
diff --git a/platform/pulpcore/app/tasks/importer.py b/platform/pulpcore/app/tasks/importer.py
index 0ef18a8..bab5d76 100644
--- a/platform/pulpcore/app/tasks/importer.py
+++ b/platform/pulpcore/app/tasks/importer.py
@@ -51,6 +51,12 @@ def delete(repo_name, importer_name):
     models.Importer.objects.filter(name=importer_name, repository__name=repo_name).delete()


+class SomeError(Exception):
+    def __init__(self, url):
+        self.url = url
+        super().__init__()
+
+
 @shared_task(base=UserFacingTask)
 def sync(repo_name, importer_name):
     """
@@ -72,4 +78,5 @@ def sync(repo_name, importer_name):

     with storage.working_dir_context() as working_dir:
         importer.working_dir = working_dir
+        raise SomeError('asdf')
         importer.sync()

When you call a sync() task, you'll experience the following exception:

Aug 22 17:22:03 pulp3 celery[22903]: [2017-08-22 17:22:03,336: ERROR/ForkPoolWorker-1] Task failed : [65f60bc5-6433-4dda-a5c0-22b22c82ceb0]
Aug 22 17:22:03 pulp3 celery[22903]: [2017-08-22 17:22:03,342: ERROR/ForkPoolWorker-1] Task pulpcore.app.tasks.importer.sync[65f60bc5-6433-4dda-a5c0-22b22c82ceb0] raised unexpected: SomeError()
Aug 22 17:22:03 pulp3 celery[22903]: Traceback (most recent call last):
Aug 22 17:22:03 pulp3 celery[22903]:   File "/home/vagrant/.virtualenvs/pulp/lib/python3.5/site-packages/celery/app/trace.py", line 374, in trace_task
Aug 22 17:22:03 pulp3 celery[22903]:     R = retval = fun(*args, **kwargs)
Aug 22 17:22:03 pulp3 celery[22903]:   File "/home/vagrant/devel/pulp/platform/pulpcore/tasking/tasks.py", line 272, in __call__
Aug 22 17:22:03 pulp3 celery[22903]:     return super(UserFacingTask, self).__call__(*args, **kwargs)
Aug 22 17:22:03 pulp3 celery[22903]:   File "/home/vagrant/.virtualenvs/pulp/lib/python3.5/site-packages/celery/app/trace.py", line 629, in __protected_call__
Aug 22 17:22:03 pulp3 celery[22903]:     return self.run(*args, **kwargs)
Aug 22 17:22:03 pulp3 celery[22903]:   File "/home/vagrant/devel/pulp/platform/pulpcore/app/tasks/importer.py", line 81, in sync
Aug 22 17:22:03 pulp3 celery[22903]:     raise SomeError('asdf')
Aug 22 17:22:03 pulp3 celery[22903]: pulpcore.app.tasks.importer.SomeError
Aug 22 17:22:03 pulp3 celery[22903]: [2017-08-22 17:22:03,344: ERROR/MainProcess] Task handler raised error: <MaybeEncodingError: Error sending result: ''(1, <ExceptionInfo: SomeError()>, None)''. Reason: ''PicklingError("Can\'t pickle <class \'pulpcore.app.tasks.importer.SomeError\'>: it\'s not the same object as pulpcore.app.tasks.importer.SomeError",)''.>
Aug 22 17:22:03 pulp3 celery[22903]: Traceback (most recent call last):
Aug 22 17:22:03 pulp3 celery[22903]:   File "/home/vagrant/.virtualenvs/pulp/lib/python3.5/site-packages/billiard/pool.py", line 362, in workloop
Aug 22 17:22:03 pulp3 celery[22903]:     put((READY, (job, i, result, inqW_fd)))
Aug 22 17:22:03 pulp3 celery[22903]:   File "/home/vagrant/.virtualenvs/pulp/lib/python3.5/site-packages/billiard/queues.py", line 366, in put
Aug 22 17:22:03 pulp3 celery[22903]:     self.send_payload(ForkingPickler.dumps(obj))
Aug 22 17:22:03 pulp3 celery[22903]:   File "/home/vagrant/.virtualenvs/pulp/lib/python3.5/site-packages/billiard/reduction.py", line 56, in dumps
Aug 22 17:22:03 pulp3 celery[22903]:     cls(buf, protocol).dump(obj)
Aug 22 17:22:03 pulp3 celery[22903]: billiard.pool.MaybeEncodingError: Error sending result: ''(1, <ExceptionInfo: SomeError()>, None)''. Reason: ''PicklingError("Can\'t pickle <class \'pulpcore.app.tasks.importer.SomeError\'>: it\'s not the same object as pulpcore.app.tasks.importer.SomeError",)''.

However with this diff:

[bmbouter@localhost pulp]$ git diff platform/pulpcore/app/tasks/importer.py
diff --git a/platform/pulpcore/app/tasks/importer.py b/platform/pulpcore/app/tasks/importer.py
index 0ef18a8..023d0c3 100644
--- a/platform/pulpcore/app/tasks/importer.py
+++ b/platform/pulpcore/app/tasks/importer.py
@@ -51,6 +51,12 @@ def delete(repo_name, importer_name):
     models.Importer.objects.filter(name=importer_name, repository__name=repo_name).delete()


+class SomeError(Exception):
+    def __init__(self):
+        self.url = 'this does not matter'
+        super().__init__()
+
+
 @shared_task(base=UserFacingTask)
 def sync(repo_name, importer_name):
     """
@@ -72,4 +78,5 @@ def sync(repo_name, importer_name):

     with storage.working_dir_context() as working_dir:
         importer.working_dir = working_dir
+        raise SomeError()
         importer.sync()

When you call the sync() task you'll receive this traceback:

Aug 22 17:26:23 pulp3 celery[23021]: [2017-08-22 17:26:23,720: ERROR/ForkPoolWorker-1] Task failed : [7b33c9a3-d13f-45cf-a510-c16f3b18deeb]
Aug 22 17:26:23 pulp3 celery[23021]: [2017-08-22 17:26:23,724: ERROR/ForkPoolWorker-1] Task pulpcore.app.tasks.importer.sync[7b33c9a3-d13f-45cf-a510-c16f3b18deeb] raised unexpected: SomeError()
Aug 22 17:26:23 pulp3 celery[23021]: Traceback (most recent call last):
Aug 22 17:26:23 pulp3 celery[23021]:   File "/home/vagrant/.virtualenvs/pulp/lib/python3.5/site-packages/celery/app/trace.py", line 374, in trace_task
Aug 22 17:26:23 pulp3 celery[23021]:     R = retval = fun(*args, **kwargs)
Aug 22 17:26:23 pulp3 celery[23021]:   File "/home/vagrant/devel/pulp/platform/pulpcore/tasking/tasks.py", line 272, in __call__
Aug 22 17:26:23 pulp3 celery[23021]:     return super(UserFacingTask, self).__call__(*args, **kwargs)
Aug 22 17:26:23 pulp3 celery[23021]:   File "/home/vagrant/.virtualenvs/pulp/lib/python3.5/site-packages/celery/app/trace.py", line 629, in __protected_call__
Aug 22 17:26:23 pulp3 celery[23021]:     return self.run(*args, **kwargs)
Aug 22 17:26:23 pulp3 celery[23021]:   File "/home/vagrant/devel/pulp/platform/pulpcore/app/tasks/importer.py", line 81, in sync
Aug 22 17:26:23 pulp3 celery[23021]:     raise SomeError()
Aug 22 17:26:23 pulp3 celery[23021]: pulpcore.app.tasks.importer.SomeError