Using 'root' in pyproject.toml file raises a TypeError when invoked from __main__.py

[FedericoVaga]

Hello,

I'm using the following versions

setuptools          50.3.2
setuptools-scm      6.4.2

I've a pyproject.toml file which setuptools_scm section is

   [tool.setuptools_scm]                                                                                                                                                                                                            
   write_to = "_version.txt"                                                                                                                                                                                                  
   root = "../.."                                                                                                                                                                                                                   
   relative_to = "__file__" 

When used with python3 -m build it works. However, when I run just tool to see the output version, I get the following

$ python -m setuptools_scm       
Traceback (most recent call last):
  File "<some-path>/lib/python3.7/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "<some-path>/lib/python3.7/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "<some-path>/lib/python3.7/site-packages/setuptools_scm/__main__.py", line 83, in <module>
    main()
  File "<some-path>/lib/python3.7/site-packages/setuptools_scm/__main__.py", line 18, in main
    config = Configuration.from_file(pyproject, root=root)
  File "<some-path>/lib/python3.7/site-packages/setuptools_scm/config.py", line 216, in from_file
    return cls(dist_name=dist_name, **section, **kwargs)
TypeError: type object got multiple values for keyword argument 'root'

The variable "root" get defined twice, first by __main__.py when setting the default 'root' or the one from the command line (--root); and the second time by the user (me) when I add 'root' to my pyproject.toml file

[GDYendell]

I have experienced the same problem. Hopefully the linked PR will fix it.