Satellite 6 Capsule installation fails, " [ERROR][MainThread] gofer.agent.plugin:535 - plugin "katelloplugin", import failed."

Issue

• I'm trying to install capules at remote locations, I've followed the documentation up to running the capsule-installer command, and I'm getting the same error at multiple sites:

[root@mycapsule1 ~]# capsule-installer --parent-fqdn          "wxyzsat6.example.local"                    --register-in-foreman  "true"                    --foreman-oauth-key    "xmmQCGYdkoCRcbviGfuPdX7ZiCsdExf"                    --foreman-oauth-secret "w5ZDpyPJ24eSBNo53AFybcnqoDYXgLUA"                    --pulp-oauth-secret    "doajBEXqNcANy93ZbciFyysWaiwt6BWU"                    --certs-tar            "/root/mycapsule1.example-certs.tar"                    --puppet               "true"                    --puppetca             "true"                    --pulp                 "true"

system identity: aaaaa-12345-67899-098765
 Execution of '/usr/bin/yum install -y mycapsule1.example.local-qpid-client-cert' returned 1: Plugin "package_upload" can't be imported
 Nothing to do
 /Stage[main]/Certs::Pulp_child/Cert[mycapsule1.example.local-qpid-client-cert]/ensure: change from absent to present failed: Execution of '/usr/bin/yum install -y mycapsule1-qpid-client-cert' returned 1: Plugin "package_upload" can't be imported
 Nothing to do
 Execution of '/usr/bin/yum install -y mycapsule1.example.local-apache' returned 1: Plugin "package_upload" can't be imported
 Nothing to do
 /Stage[main]/Certs::Apache/Cert[mycapsule1.example.local-apache]/ensure: change from absent to present failed: Execution of '/usr/bin/yum install -y mycapsule1.example.local-apache' returned 1: Plugin "package_upload" can't be imported
 Nothing to do
 Execution of '/usr/bin/yum install -y mycapsule1.example.local-puppet-client' returned 1: Plugin "package_upload" can't be imported
 Nothing to do
 /Stage[main]/Certs::Puppet/Cert[mycapsule1.example.local-puppet-client]/ensure: change from absent to present failed: Execution of '/usr/bin/yum install -y mycapsule1.example.local-puppet-client' returned 1: Plugin "package_upload" can't be imported
 Nothing to do
 Execution of '/usr/bin/yum install -y mycapsule1.example.local-qpid-broker' returned 1: Plugin "package_upload" can't be imported
 Nothing to do
 /Stage[main]/Certs::Qpid/Cert[mycapsule1.example.locall-qpid-broker]/ensure: change from absent to present failed: Execution of '/usr/bin/yum install -y mycapsule1.example.local-qpid-broker' returned 1: Plugin "package_upload" can't be imported
 Nothing to do
 Execution of '/usr/bin/yum install -y mycapsule1.example.local-foreman-proxy' returned 1: Plugin "package_upload" can't be imported
 Nothing to do
 /Stage[main]/Certs::Foreman_proxy/Cert[mycapsule1.example.local-foreman-proxy]/ensure: change from absent to present failed: Execution of '/usr/bin/yum install -y mycapsule1.example.local-foreman-proxy' returned 1: Plugin "package_upload" can't be imported
 Nothing to do
Installing             Done                                               [100%] [.........................................................................................................................................................]
  Something went wrong! Check the log for ERROR-level output
  The full log is at /var/log/katello-installer/capsule-installer.log
[root@mycapsule1 ~]#

• Log shows the following errors:

Dec 22 16:46:45 mycapsule1 goferd: [INFO][MainThread] gofer.agent.plugin:521 - plugin [builtin] loaded using: /usr/share/gofer/plugins/builtin.py
Dec 22 16:46:45 mycapsule1 yum[34191]: Installed: katello-agent-1.5.3-5.el6sat.noarch
Dec 22 16:46:45 mycapsule1 goferd: [ERROR][MainThread] gofer.agent.plugin:535 - plugin "katelloplugin", import failed
Dec 22 16:46:45 mycapsule1 goferd: [ERROR][MainThread] gofer.agent.plugin:535 - Traceback (most recent call last): File "/usr/lib/python2.6/site-packages/gofer/agent/plugin.py", line 519, in _import plugin.impl = imp.load_source(name, path) File "/usr/lib/gofer/plugins/katelloplugin.py", line 33, in <module> from subscription_manager.certlib import ConsumerIdentity ImportError: cannot import name ConsumerIdentity