Description of problem:
FormatCreateError: 'invalid device specification'

While trying FC21 Alpha TC4 with test detailed in
https://fedoraproject.org/wiki/QA:Testcase_kickstart_firewall

Version-Release number of selected component:
anaconda-21.48.6-1

The following was filed automatically by anaconda:
anaconda 21.48.6-1 exception report
Traceback (most recent call first):
  File "/usr/lib/python2.7/site-packages/blivet/formats/__init__.py", line 370, in create
    raise FormatCreateError("invalid device specification", self.device)
  File "/usr/lib/python2.7/site-packages/blivet/formats/prepboot.py", line 76, in create
    DeviceFormat.create(self, **kwargs)
  File "/usr/lib/python2.7/site-packages/blivet/deviceaction.py", line 554, in execute
    options=self.device.formatArgs)
  File "/usr/lib/python2.7/site-packages/blivet/devicetree.py", line 354, in processActions
    action.execute()
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 354, in doIt
    self.devicetree.processActions()
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 214, in turnOnFilesystems
    storage.doIt()
  File "/usr/lib64/python2.7/site-packages/pyanaconda/install.py", line 178, in doInstall
    turnOnFilesystems(storage, mountOnly=flags.flags.dirInstall)
  File "/usr/lib64/python2.7/threading.py", line 766, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/usr/lib64/python2.7/site-packages/pyanaconda/threads.py", line 227, in run
    threading.Thread.run(self, *args, **kwargs)
FormatCreateError: ('invalid device specification', '/dev/sda1')

Additional info:
addons:         com_redhat_kdump
cmdline:        /usr/bin/python  /sbin/anaconda
cmdline_file:   BOOT_IMAGE=/ppc/ppc64/vmlinuz inst.ks=http://fedorapeople.org/groups/qa/kickstarts/firewall-disabled-net.ks
executable:     /sbin/anaconda
hashmarkername: anaconda
kernel:         3.16.2-301.fc21.ppc64le
product:        Fedora"
release:        Cannot get release name.
type:           anaconda
version:        Fedora