Description of problem:
I'm encountering an issue with a kickstart installation of Fedora 30 (and 29) on a system with a single SATA SSD for the operating system, /dev/sda, and a 3.0 TB NVMe SSD, /dev/nvme0n1.

The following kickstart metadata item is added to ensure that the install only occurs on /dev/sda:

"ignoredisk --only-use=sda"

After that, the Fedora installation is executed via beaker.  The install fails at the error string "pyanaconda.modules.common.errors.DBusError: expected str, bytes or os.PathLike object, not NoneType".

(This seems similar to the output of BZ 1698937, but it may be a different scenario.)

Note that if I go to the console of the system, I can see both /dev/sda and /dev/nvme0n1 in lsblk, /sys/block, etc.

Version-Release number of selected component (if applicable):
anaconda 30.25.6-2.fc30

How reproducible:
100% if the NVMe device is installed.


Actual results:
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:ERROR:pydbus.registration:Exception while handling org.fedoraproject.Anaconda.Modules.ReadKickstart()
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:Traceback (most recent call last):
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib/python3.7/site-packages/pydbus/registration.py", line 82, in call_method
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    result = method(*parameters, **kwargs)
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib64/python3.7/site-packages/pyanaconda/dbus/property.py", line 45, in wrapper
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    result = method(obj, *args, **kwargs)
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib64/python3.7/site-packages/pyanaconda/modules/common/base/base_interface.py", line 88, in ReadKickstart
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    self.implementation.read_kickstart(kickstart)
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib64/python3.7/site-packages/pyanaconda/modules/common/base/base.py", line 209, in read_kickstart
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    parser.readKickstartFromString(s)
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib/python3.7/site-packages/pykickstart/parser.py", line 792, in readKickstartFromString
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    self._stateMachine(i)
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib/python3.7/site-packages/pykickstart/parser.py", line 775, in _stateMachine
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    self._tryFunc(lambda: self.handleCommand(lineno, args))
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib/python3.7/site-packages/pykickstart/parser.py", line 686, in _tryFunc
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    fn()
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib/python3.7/site-packages/pykickstart/parser.py", line 775, in <lambda>
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    self._tryFunc(lambda: self.handleCommand(lineno, args))
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib/python3.7/site-packages/pykickstart/parser.py", line 577, in handleCommand
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    retval = self.handler.dispatcher(args, lineno)
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib/python3.7/site-packages/pykickstart/base.py", line 385, in dispatcher
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    obj = self.commands[cmd].parse(args[1:])
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib64/python3.7/site-packages/pyanaconda/modules/storage/kickstart.py", line 120, in parse
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    msg=_("Disk \"{}\" given in ignoredisk command does "
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib64/python3.7/site-packages/pyanaconda/modules/storage/kickstart.py", line 44, in get_device_names
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    matched = device_matches(spec, disks_only=disks_only)
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib64/python3.7/site-packages/pyanaconda/storage/utils.py", line 298, in device_matches
21:04:21,166 WARNING org.fedoraproject.Anaconda.Modules.Storage:    single_spec_matches = udev.resolve_glob(full_spec)
21:04:21,167 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib/python3.7/site-packages/blivet/udev.py", line 167, in resolve_glob
21:04:21,167 WARNING org.fedoraproject.Anaconda.Modules.Storage:    if fnmatch.fnmatch(name, glob) or fnmatch.fnmatch(path, glob):
21:04:21,167 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib64/python3.7/fnmatch.py", line 34, in fnmatch
21:04:21,167 WARNING org.fedoraproject.Anaconda.Modules.Storage:    name = os.path.normcase(name)
21:04:21,167 WARNING org.fedoraproject.Anaconda.Modules.Storage:  File "/usr/lib64/python3.7/posixpath.py", line 54, in normcase
21:04:21,167 WARNING org.fedoraproject.Anaconda.Modules.Storage:    s = os.fspath(s)
21:04:21,167 WARNING org.fedoraproject.Anaconda.Modules.Storage:TypeError: expected str, bytes or os.PathLike object, not NoneType
21:04:21,167 WARNING org.fedoraproject.Anaconda.Modules.Storage:INFO:pydbus.registration:name is not registered
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:ERROR:pydbus.registration:Exception while handling org.fedoraproject.Anaconda.Boss.Anaconda.DistributeKickstart()
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:Traceback (most recent call last):
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:  File "/usr/lib/python3.7/site-packages/pydbus/registration.py", line 82, in call_method
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:    result = method(*parameters, **kwargs)
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:  File "/usr/lib64/python3.7/site-packages/pyanaconda/modules/boss/boss_interface.py", line 79, in DistributeKickstart
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:    results = self.implementation.distribute_kickstart()
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:  File "/usr/lib64/python3.7/site-packages/pyanaconda/modules/boss/boss.py", line 125, in distribute_kickstart
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:    return self._kickstart_manager.distribute()
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:  File "/usr/lib64/python3.7/site-packages/pyanaconda/modules/boss/kickstart_manager/kickstart_manager.py", line 108, in distribute
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:    result = observer.proxy.ReadKickstart(kickstart)
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:  File "/usr/lib/python3.7/site-packages/pydbus/proxy_method.py", line 102, in __call__
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:    raise error
21:04:21,168 WARNING org.fedoraproject.Anaconda.Boss:pyanaconda.modules.common.errors.DBusError: expected str, bytes or os.PathLike object, not NoneType


Expected results:
Anaconda is able to use /dev/sda to install Fedora, and the installation succeeds.

Additional info: