Description of problem:
Boot Fedora 23 Alpha RC2 server netinst on system with Intel software RAID (IMSM), with partitions on RAID device.

Version-Release number of selected component:
anaconda-23.17-1

The following was filed automatically by anaconda:
anaconda 23.17-1 exception report
Traceback (most recent call first):
  File "/usr/lib/python3.4/site-packages/blivet/devices/storage.py", line 604, in currentSize
    if self._currentSize == Size(0):
  File "/usr/lib/python3.4/site-packages/blivet/devices/md.py", line 681, in _addParent
    self._size = self.currentSize
  File "/usr/lib/python3.4/site-packages/blivet/devices/lib.py", line 156, in append
    self.appendfunc(y)
  File "/usr/lib/python3.4/site-packages/blivet/devices/device.py", line 153, in _setParentList
    self._parents.append(parent)
  File "/usr/lib/python3.4/site-packages/blivet/devices/device.py", line 89, in __init__
    self.parents = parents or []
  File "/usr/lib/python3.4/site-packages/blivet/devices/storage.py", line 107, in __init__
    super(StorageDevice, self).__init__(name, parents=parents)
  File "/usr/lib/python3.4/site-packages/blivet/devices/container.py", line 63, in __init__
    super(ContainerDevice, self).__init__(*args, **kwargs)
  File "/usr/lib/python3.4/site-packages/blivet/devices/md.py", line 112, in __init__
    sysfsPath=sysfsPath)
  File "/usr/lib/python3.4/site-packages/blivet/devices/md.py", line 631, in __init__
    super(MDBiosRaidArrayDevice, self).__init__(name, **kwargs)
  File "/usr/lib/python3.4/site-packages/blivet/populator.py", line 568, in addUdevDiskDevice
    sysfsPath=sysfs_path, **kwargs)
  File "/usr/lib/python3.4/site-packages/blivet/populator.py", line 721, in addUdevDevice
    device = self.addUdevDiskDevice(info)
  File "/usr/lib/python3.4/site-packages/blivet/populator.py", line 1660, in _populate
    self.addUdevDevice(dev)
  File "/usr/lib/python3.4/site-packages/blivet/populator.py", line 1597, in populate
    self._populate()
  File "/usr/lib/python3.4/site-packages/blivet/devicetree.py", line 554, in populate
    self._populator.populate(cleanupOnly=cleanupOnly)
  File "/usr/lib/python3.4/site-packages/blivet/blivet.py", line 279, in reset
    self.devicetree.populate(cleanupOnly=cleanupOnly)
  File "/usr/lib/python3.4/site-packages/blivet/osinstall.py", line 1123, in storageInitialize
    storage.reset()
  File "/usr/lib64/python3.4/threading.py", line 868, in run
    self._target(*self._args, **self._kwargs)
  File "/usr/lib64/python3.4/site-packages/pyanaconda/threads.py", line 253, in run
    threading.Thread.run(self, *args, **kwargs)
AttributeError: 'MDBiosRaidArrayDevice' object has no attribute '_currentSize'

Additional info:
addons:         com_redhat_kdump
cmdline:        /usr/bin/python3  /sbin/anaconda
cmdline_file:   BOOT_IMAGE=vmlinuz initrd=initrd.img inst.stage2=hd:LABEL=Fedora-S-23_A_T2-x86_64 rd.driver.blacklist=bcache
dnf.rpm.log:    Aug 07 10:36:31 INFO --- logging initialized ---
executable:     /sbin/anaconda
hashmarkername: anaconda
kernel:         4.2.0-0.rc3.git4.1.fc23.x86_64
product:        Fedora
release:        Cannot get release name.
type:           anaconda
version:        23