Today I deleted a mirror of rhel-6, and then recreated it with the exact same settings. I had not synced the deleted rhel-6 in a while (days). After creating the new rhel-6 and syncing, I was unable to publish.

rbarlow@guava ~/d/p/pulp> 
pulp-admin rpm repo create --repo-id rhel-6-server --feed=https://cdn.redhat.com/content/dist/rhel/server/6/6Server/x86_64/os --feed-ca-cert=/home/rbarlow/redhat-uep.pem --feed-cert=/home/rbarlow/****.pem --feed-key /home/rbarlow/****-key.pem

rbarlow@guava ~/d/p/pulp> pulp-admin rpm repo publish run --repo-id rhel-6-server
+----------------------------------------------------------------------+
                 Publishing Repository [rhel-6-server]
+----------------------------------------------------------------------+

This command may be exited via ctrl+c without affecting the request.


Publishing Distribution files
[-]
... completed

Publishing RPMs
[                                                  ] 0%
0 of 12527 items

Task Failed

Pulp exception occurred: PulpExecutionException

Here is the relevant bit of the logs:

celery.worker.strategy:INFO: Received task: pulp.server.managers.repo.publish.publish[a251eaff-c9de-4f5e-ad85-3356a5dc4c3d]
celery.worker.strategy:INFO: Received task: pulp.server.async.tasks._queue_release_resource[64c5cbfc-d6ff-4723-ba31-890767020610]
celery.worker.job:INFO: Task pulp.server.tasks.repository.sync_with_auto_publish[24ca3aad-52b5-4eb9-a163-bc15facec00c] succeeded in 876.964413444s: <pulp.server.async.tasks.TaskResult object at 0x31df210>
celery.worker.strategy:INFO: Received task: pulp.server.async.tasks._release_resource[8b06bb8f-bc50-4c54-b899-353f1328c8c2]
celery.worker.job:INFO: Task pulp.server.async.tasks._queue_release_resource[c8c20ce2-fdeb-46f3-9b5d-e991a524f610] succeeded in 0.0379554569954s: None
celery.worker.job:INFO: Task pulp.server.async.tasks._release_resource[8b06bb8f-bc50-4c54-b899-353f1328c8c2] succeeded in 0.0232481429994s: None
celery.worker.job:INFO: Task pulp.server.async.tasks.babysit[fea8da63-dbad-401c-aa00-519d3bc54778] succeeded in 1.16808687799s: None
py.warnings:WARNING: /usr/lib/python2.7/site-packages/celery/app/control.py:34: DuplicateNodenameWarning: Received multiple replies from node name True.
py.warnings:WARNING: Please make sure you give each node a unique nodename using the `-n` option.
py.warnings:WARNING:   W_DUPNODE.format(dup),
py.warnings:WARNING:
celery.worker.job:INFO: Task pulp.server.async.tasks.babysit[c3d6abb1-e132-407d-a61f-a3247b945ab1] succeeded in 1.29009989899s: None
celery.worker.job:INFO: Task pulp.server.async.tasks.babysit[55ae9f20-028d-43fe-b12a-914ee50d31d3] succeeded in 1.233596609s: None
celery.worker.job:INFO: Task pulp.server.async.tasks.babysit[cdfe3d60-78c5-409e-867b-b09ee64268a6] succeeded in 1.280725091s: None
pulp.server.managers.repo.publish:ERROR: Exception caught from plugin during publish for repo [rhel-6-server]
pulp.server.managers.repo.publish:ERROR: Traceback (most recent call last):
pulp.server.managers.repo.publish:ERROR:   File "/home/rbarlow/devel/pulp/pulp/server/pulp/server/managers/repo/publish.py", line 126, in _do_publish
pulp.server.managers.repo.publish:ERROR:     publish_report = publish_repo(transfer_repo, conduit, call_config)
pulp.server.managers.repo.publish:ERROR:   File "/home/rbarlow/devel/pulp/pulp/server/pulp/server/async/tasks.py", line 543, in wrap_f
pulp.server.managers.repo.publish:ERROR:     return f(*args, **kwargs)
pulp.server.managers.repo.publish:ERROR:   File "/home/rbarlow/devel/pulp/pulp_rpm/plugins/pulp_rpm/plugins/distributors/yum/distributor.py", line 130, in publish_repo
pulp.server.managers.repo.publish:ERROR:     return self._publisher.publish()
pulp.server.managers.repo.publish:ERROR:   File "/home/rbarlow/devel/pulp/pulp/server/pulp/plugins/util/publish_step.py", line 169, in publish
pulp.server.managers.repo.publish:ERROR:     step.process()
pulp.server.managers.repo.publish:ERROR:   File "/home/rbarlow/devel/pulp/pulp/server/pulp/plugins/util/publish_step.py", line 368, in process
pulp.server.managers.repo.publish:ERROR:     self._process_block()
pulp.server.managers.repo.publish:ERROR:   File "/home/rbarlow/devel/pulp/pulp/server/pulp/plugins/util/publish_step.py", line 603, in _process_block
pulp.server.managers.repo.publish:ERROR:     self.process_unit(package_unit)
pulp.server.managers.repo.publish:ERROR:   File "/home/rbarlow/devel/pulp/pulp_rpm/plugins/pulp_rpm/plugins/distributors/yum/publish.py", line 157, in process_unit
pulp.server.managers.repo.publish:ERROR:     self._create_symlink(source_path, destination_path)
pulp.server.managers.repo.publish:ERROR:   File "/home/rbarlow/devel/pulp/pulp/server/pulp/plugins/util/publish_step.py", line 427, in _create_symlink
pulp.server.managers.repo.publish:ERROR:     raise RuntimeError(msg % {'s': source_path})
pulp.server.managers.repo.publish:ERROR: RuntimeError: Will not create a symlink to a non-existent source [/var/lib/pulp/content/rpm/389-ds-base/1.2.10.2/15.el6/x86_64/e0c7dbd9b0d6ef7c1cee92bc3e6d8a41e5f4df3e/389-ds-base-1.2.10.2-15.el6.x86_64.rpm]