为什么 leapp preupgrade 失败并显示 'sqlite3.OperationalError: unable to open database file' 回溯错误?

Issue

• Leapp preupgrade 命令失败并显示回溯错误：

# leapp preupgrade
Traceback (most recent call last):
  File "/usr/bin/leapp", line 9, in <module>
    load_entry_point('leapp==0.12.1', 'console_scripts', 'leapp')()
  File "/usr/lib/python2.7/site-packages/leapp/cli/__init__.py", line 18, in main
    cli.command.execute('leapp version {}'.format(VERSION))
  File "/usr/lib/python2.7/site-packages/leapp/utils/clicmd.py", line 105, in execute
    args.func(args)
  File "/usr/lib/python2.7/site-packages/leapp/utils/clicmd.py", line 127, in called
    self.target(args)
  File "/usr/lib/python2.7/site-packages/leapp/cli/upgrade/__init__.py", line 352, in preupgrade
    e.store()
  File "/usr/lib/python2.7/site-packages/leapp/utils/audit/__init__.py", line 79, in store
    self.do_store(connection)
  File "/usr/lib/python2.7/site-packages/leapp/utils/audit/__init__.py", line 126, in do_store
    (self.context, self.configuration, self.stamp, self.kind))
sqlite3.OperationalError: unable to open database file