Description of problem:
trying to install fedora 20 using bfo. This error happened after choose keyboard type.

Version-Release number of selected component:
anaconda-20.25.15-1

The following was filed automatically by anaconda:
anaconda 20.25.15-1 exception report
Traceback (most recent call first):
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 3137, in parseFSTab
    swaps.append(device)
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 3052, in findExistingInstallations
    (mounts, swaps) = parseFSTab(devicetree, chroot=ROOT_PATH)
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 427, in reset
    self.roots = findExistingInstallations(self.devicetree)
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 142, in storageInitialize
    storage.reset()
  File "/usr/lib64/python2.7/threading.py", line 764, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/usr/lib64/python2.7/site-packages/pyanaconda/threads.py", line 192, in run
    threading.Thread.run(self, *args, **kwargs)
IOError: [Errno 9] Descritor de arquivo inválido

Additional info:
cmdline:        /usr/bin/python  /sbin/anaconda
cmdline_file:   repo=http://download.fedoraproject.org/pub/fedora/linux/releases/20/Fedora/x86_64/os/ initrd=http://download.fedoraproject.org/pub/fedora/linux/releases/20/Fedora/x86_64/os/images/pxeboot/initrd.img BOOT_IMAGE=http://download.fedoraproject.org/pub/fedora/linux/releases/20/Fedora/x86_64/os/images/pxeboot/vmlinuz 
executable:     /sbin/anaconda
hashmarkername: anaconda
kernel:         3.11.10-301.fc20.x86_64
product:        Fedora
release:        Cannot get release name.
type:           anaconda
version:        20