Description of problem:
when we installed Fedora-rawhide from http://dl.fedoraproject.org/pub/fedora/linux/development/rawhide/x86_64/os/, we got an exception
anaconda 21.40-1 exception report 
Traceback (most recent call first):      
  
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 367, in doIt 
    if boot.type == "mdarray": 
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 215, in turnOnFilesystems 
    storage.doIt() 
  File "/usr/lib64/python2.7/site-packages/pyanaconda/install.py", line 179, 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) 
AttributeError: 'NoneType' object has no attribute 'type' 

Version-Release number of selected component (if applicable):
anaconda 21.40-1

How reproducible:
always

Steps to Reproduce:
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Actual results:


Expected results:


Additional info: