python -m pdm list get an error

[stacklens]

Environment: Windows 10, Python 3.7

When the library is empty, the following error occurs during python -m pdm list:

C:\Users\dusai>python -m pdm add cowsay
Adding packages to default dependencies: cowsay
Traceback (most recent call last):
  File "C:\Users\dusai\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "C:\Users\dusai\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Users\dusai\AppData\Roaming\Python\Python37\site-packages\pdm\__main__.py", line 4, in <module>
    cli.main()
  File "C:\Users\dusai\AppData\Local\Programs\Python\Python37\lib\site-packages\click\core.py", line 697, in main
    rv = self.invoke(ctx)
  File "C:\Users\dusai\AppData\Local\Programs\Python\Python37\lib\site-packages\click\core.py", line 1066, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "C:\Users\dusai\AppData\Local\Programs\Python\Python37\lib\site-packages\click\core.py", line 895, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "C:\Users\dusai\AppData\Local\Programs\Python\Python37\lib\site-packages\click\core.py", line 535, in invoke
    return callback(*args, **kwargs)
  File "C:\Users\dusai\AppData\Local\Programs\Python\Python37\lib\site-packages\click\decorators.py", line 64, in new_func
    return ctx.invoke(f, obj, *args[1:], **kwargs)
  File "C:\Users\dusai\AppData\Local\Programs\Python\Python37\lib\site-packages\click\core.py", line 535, in invoke
    return callback(*args, **kwargs)
  File "C:\Users\dusai\AppData\Roaming\Python\Python37\site-packages\pdm\cli\commands.py", line 161, in add
    actions.do_add(project, dev, section, sync, save, strategy, editables, packages)
  File "C:\Users\dusai\AppData\Roaming\Python\Python37\site-packages\pdm\cli\actions.py", line 175, in do_add
    project.add_dependencies(requirements)
  File "C:\Users\dusai\AppData\Roaming\Python\Python37\site-packages\pdm\project\core.py", line 261, in add_dependencies
    deps = self.tool_settings["dependencies"]
  File "C:\Users\dusai\AppData\Roaming\Python\Python37\site-packages\pdm\project\core.py", line 35, in getter
    _cache = func(self, *args, **kwargs)
  File "C:\Users\dusai\AppData\Roaming\Python\Python37\site-packages\pdm\project\core.py", line 91, in tool_settings
    data = data.setdefault(sec, {})
AttributeError: 'NoneType' object has no attribute 'setdefault'

When the library has any sitepackage, the error disappears:

C:\Users\dusai>python -m pdm list
pdmtest  1.0.0 (-e c:\users\dusai)
cowsay   2.0.3

😆😆😆It's a great tool. Keep going!😆😆😆