Description of problem:
selecting checkbox "Manually specify layout" for device type LVM2 Volume Group, while selecting two available devices (170GiB and 5MiB)

Version-Release number of selected component:
anaconda-core-26.21.1-1.fc26.x86_64

The following was filed automatically by anaconda:
anaconda 26.21.1-1 exception report
Traceback (most recent call first):
  File "/usr/lib/python3.6/site-packages/blivetgui/dialogs/size_chooser.py", line 731, in selected_size
    raise ValueError("New size must be between minimal (%s) and maximum (%s) size." % (self.min_size, self.max_size))
  File "/usr/lib/python3.6/site-packages/blivetgui/dialogs/size_chooser.py", line 721, in __init__
    self.selected_size = max_size
  File "/usr/lib/python3.6/site-packages/blivetgui/dialogs/size_chooser.py", line 586, in __init__
    self.size_chooser = SizeChooser(max_size=max_size, min_size=min_size)
  File "/usr/lib/python3.6/site-packages/blivetgui/dialogs/size_chooser.py", line 499, in _add_parent_choosers
    size_selectable=size_selectable)
  File "/usr/lib/python3.6/site-packages/blivetgui/dialogs/size_chooser.py", line 372, in __init__
    self._add_parent_choosers()
  File "/usr/lib/python3.6/site-packages/blivetgui/dialogs/size_chooser.py", line 299, in _add_advanced_area
    self._parent_area = ParentArea(self.device_type, self.parents, self.raid_type, self.main_chooser)
  File "/usr/lib/python3.6/site-packages/blivetgui/dialogs/size_chooser.py", line 344, in _on_manual_toggled
    self._add_advanced_area()
ValueError: New size must be between minimal (8 MiB) and maximum (5 MiB) size.

Additional info:
addons:         com_redhat_kdump
cmdline:        /usr/libexec/system-python  /sbin/anaconda --liveinst --method=livecd:///dev/mapper/live-base
executable:     /sbin/anaconda
hashmarkername: anaconda
kernel:         4.11.0-0.rc3.git0.2.fc26.x86_64
other involved packages: blivet-gui-2.1.1-1.fc26.noarch
product:        Fedora
release:        Fedora release 26 (Twenty Six)
type:           anaconda
version:        26