Description of problem:
I tried to run:
~~~
$ sudo subscription-manager register
~~~

Version-Release number of selected component:
subscription-manager-1.23.3-1.fc29

Additional info:
reporter:       libreport-2.9.5
cmdline:        /usr/bin/python3 /usr/sbin/subscription-manager register
crash_function: read
exception_type: FileNotFoundError
executable:     /usr/sbin/subscription-manager
interpreter:    python3-3.7.0-9.fc29.x86_64
kernel:         4.18.11-300.fc29.x86_64
runlevel:       N 5
type:           Python3
uid:            0

Truncated backtrace:
identity.py:147:reload:AttributeError: module 'os' has no attribute 'errno'

Traceback (most recent call last):
  File "/usr/lib64/python3.7/site-packages/subscription_manager/identity.py", line 140, in reload
    self.consumer = self._get_consumer_identity()
  File "/usr/lib64/python3.7/site-packages/subscription_manager/identity.py", line 164, in _get_consumer_identity
    return ConsumerIdentity.read()
  File "/usr/lib64/python3.7/site-packages/subscription_manager/identity.py", line 53, in read
    with open(cls.keypath()) as key_file:
FileNotFoundError: [Errno 2] No such file or directory: '/etc/pki/consumer/key.pem'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/sbin/subscription-manager", line 11, in <module>
    load_entry_point('subscription-manager==1.23.3', 'console_scripts', 'subscription-manager')()
  File "/usr/lib64/python3.7/site-packages/subscription_manager/scripts/subscription_manager.py", line 85, in main
    return managercli.ManagerCLI().main()
  File "/usr/lib64/python3.7/site-packages/subscription_manager/managercli.py", line 2838, in __init__
    CLI.__init__(self, command_classes=commands)
  File "/usr/lib64/python3.7/site-packages/subscription_manager/cli.py", line 101, in __init__
    cmd = clazz()
  File "/usr/lib64/python3.7/site-packages/subscription_manager/managercli.py", line 1056, in __init__
    super(RegisterCommand, self).__init__("register", shortdesc, True)
  File "/usr/lib64/python3.7/site-packages/subscription_manager/managercli.py", line 529, in __init__
    super(UserPassCommand, self).__init__(name, shortdesc, primary)
  File "/usr/lib64/python3.7/site-packages/subscription_manager/managercli.py", line 257, in __init__
    self.identity = inj.require(inj.IDENTITY)
  File "/usr/lib64/python3.7/site-packages/subscription_manager/injection.py", line 106, in require
    return FEATURES.require(feature, *args, **kwargs)
  File "/usr/lib64/python3.7/site-packages/subscription_manager/injection.py", line 80, in require
    self.providers[feature] = provider(*args, **kwargs)
  File "/usr/lib64/python3.7/site-packages/subscription_manager/identity.py", line 133, in __init__
    self.reload()
  File "/usr/lib64/python3.7/site-packages/subscription_manager/identity.py", line 147, in reload
    if isinstance(err, IOError) and err.errno == os.errno.ENOENT:
AttributeError: module 'os' has no attribute 'errno'

Local variables in innermost frame:
self: <subscription_manager.identity.Identity object at 0x7fef1efbea20>
msg: "Reload of consumer identity cert /etc/pki/consumer/cert.pem raised an exception with msg: [Errno 2] No such file or directory: '/etc/pki/consumer/key.pem'"