Description of problem:
All I did was 
~$ cd /etc/yum.repos.d/
/etc/yum.repos.d$ sudo su
/etc/yum.repos.d# touch vtrefny-blivet-gui.repo
/etc/yum.repos.d# vi vtrefny-blivet-gui.repo

used yumex to install blivet-gui

/etc/yum.repos.d$ blivet-gui
dm.c: 1693: not running as root returning empty list
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.
/etc/yum.repos.d$ sudo blivet-gui
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/blivetgui/devicevisualization/device_canvas.py", line 386, in draw_event
    draw_loop(self, root_iter, 0, 0, self.parent, width)
  File "/usr/lib/python2.7/site-packages/blivetgui/devicevisualization/device_canvas.py", line 360, in draw_loop
    parts_left, size_left, start, depth)
  File "/usr/lib/python2.7/site-packages/blivetgui/devicevisualization/device_canvas.py", line 184, in compute_rectangles_size
    total_size = round(parent.size.convertTo(spec="MiB"))
  File "/usr/lib/python2.7/site-packages/blivet/size.py", line 304, in convertTo
    return Decimal(self) / Decimal((spec or B).factor)
AttributeError: 'str' object has no attribute 'factor'

Version-Release number of selected component:
blivet-gui-0.2.0-6.fc22

Additional info:
reporter:       libreport-2.4.0
cmdline:        /usr/bin/python /bin/blivet-gui
dso_list:       python-blivet-1.0-1.fc22.noarch
executable:     /bin/blivet-gui
kernel:         3.20.0-0.rc0.git10.1.fc22.x86_64
runlevel:       N 3
type:           Python
uid:            0

Truncated backtrace:
size.py:304:convertTo:AttributeError: 'str' object has no attribute 'factor'

Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/blivetgui/devicevisualization/device_canvas.py", line 386, in draw_event
    draw_loop(self, root_iter, 0, 0, self.parent, width)
  File "/usr/lib/python2.7/site-packages/blivetgui/devicevisualization/device_canvas.py", line 360, in draw_loop
    parts_left, size_left, start, depth)
  File "/usr/lib/python2.7/site-packages/blivetgui/devicevisualization/device_canvas.py", line 184, in compute_rectangles_size
    total_size = round(parent.size.convertTo(spec="MiB"))
  File "/usr/lib/python2.7/site-packages/blivet/size.py", line 304, in convertTo
    return Decimal(self) / Decimal((spec or B).factor)
AttributeError: 'str' object has no attribute 'factor'

Local variables in innermost frame:
self: Size('465.76 GiB')
spec: 'MiB'