File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/gui/qt/__init__.py", line 215, in wrapper
    return func(self, *args, **kwargs)
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/gui/qt/__init__.py", line 239, in start_new_window
    wallet = self._start_wizard_to_select_or_create_wallet(path)
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/gui/qt/__init__.py", line 284, in _start_wizard_to_select_or_create_wallet
    wizard.run_upgrades(storage)
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/gui/qt/installwizard.py", line 329, in run_upgrades
    self.upgrade_storage(storage)
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/base_wizard.py", line 152, in upgrade_storage
    self.waiting_dialog(do_upgrade, _('Upgrading wallet format...'), on_finished=on_finished)
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/gui/qt/installwizard.py", line 501, in waiting_dialog
    on_finished()
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/base_wizard.py", line 145, in on_finished
    raise exc
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/base_wizard.py", line 149, in do_upgrade
    storage.upgrade()
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/storage.py", line 234, in upgrade
    self.write()
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/util.py", line 356, in <lambda>
    return lambda *args, **kw_args: do_profile(args, kw_args)
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/util.py", line 352, in do_profile
    o = func(*args, **kw_args)
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/storage.py", line 89, in write
    self._write()
  File "/tmp/.mount_electrLIWdYH/usr/lib/python3.6/site-packages/electrum/storage.py", line 100, in _write
    with open(temp_path, "w", encoding='utf-8') as f: