Wubi.exe crashes with TypeError: unsupported operand type(s) for /: 'str' and 'int' with --size command line argument

TEST CASE:
./wubi.exe --size=10000

Result:
Traceback (most recent call last):
  File "\lib\wubi\application.py", line 57, in run
  File "\lib\wubi\application.py", line 131, in select_task
  File "\lib\wubi\application.py", line 155, in run_installer
  File "\lib\wubi\frontends\win32\frontend.py", line 115, in show_installation_settings
  File "\lib\winui\ui.py", line 168, in __init__
  File "\lib\winui\ui.py", line 91, in __init__
  File "\lib\wubi\frontends\win32\installation_page.py", line 206, in on_init
  File "\lib\wubi\frontends\win32\installation_page.py", line 156, in populate_distro_list
  File "\lib\wubi\frontends\win32\installation_page.py", line 277, in on_distro_change
  File "\lib\wubi\frontends\win32\installation_page.py", line 99, in populate_drive_list
  File "\lib\wubi\frontends\win32\installation_page.py", line 115, in select_default_drive
  File "\lib\wubi\frontends\win32\installation_page.py", line 291, in on_drive_change
  File "\lib\wubi\frontends\win32\installation_page.py", line 129, in populate_size_list
  File "\lib\wubi\frontends\win32\installation_page.py", line 133, in select_default_size
TypeError: unsupported operand type(s) for /: 'str' and 'int'

This is caused by the following type conversion in wubi/frontends/win32/installation_page.py:

131- def select_default_size(self):
132: if self.info.installation_size_mb:
133: installation_size_gb = int(self.info.installation_size_mb/1000)