Decode error on Windows

[amyreese]

Seen in ufmt when running pessimist jobs on Windows: https://github.com/omnilib/ufmt/runs/6540529685?check_suite_focus=true

`-- 3.8.10
    `-- 3.8.10 deps> 'C:\hostedtoolcache\windows\Python\3.8.10\x64\python.EXE' 
        -m pessimist -c 'python -m ufmt.tests' --fast . FAIL
        Requirement already satisfied: flit_core!=3.7.0,<4,>=3 in 
        c:\hostedtoolcache\windows\python\3.8.10\x64\lib\site-packages (3.7.1)
        
        Traceback (most recent call last):
          File "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\runpy.py", 
        line 194, in _run_module_as_main
            return _run_code(code, main_globals, None,
          File "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\runpy.py", 
        line 87, in _run_code
            exec(code, run_globals)
          File "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\site-packages\
        pessimist\__main__.py", line 3, in <module>
            main(prog_name="pessimist")
          File "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\site-packages\
        click\core.py", line 1130, in __call__
            return self.main(*args, **kwargs)
          File "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\site-packages\
        click\core.py", line 1055, in main
            rv = self.invoke(ctx)
          File "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\site-packages\
        click\core.py", line 1404, in invoke
            return ctx.invoke(self.callback, **ctx.params)
          File "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\site-packages\
        click\core.py", line 760, in invoke
            return __callback(*args, **kwargs)
          File "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\site-packages\
        pessimist\cli.py", line 43, in main
            variable: List[str] = 
        get_metadata(Path(target_dir)).get_all("Requires-Dist", [])
          File "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\site-packages\
        pessimist\util.py", line 62, in get_metadata
            return Parser().parse(fp)
          File 
        "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\email\parser.py", 
        line 53, in parse
            data = fp.read(8192)
          File 
        "C:\hostedtoolcache\windows\Python\3.8.10\x64\lib\encodings\cp1252.py",
        line 23, in decode
            return codecs.charmap_decode(input,self.errors,decoding_table)[0]
        UnicodeDecodeError: 'charmap' codec can't decode byte 0x9d in position 
        1919: character maps to <undefined>
        
FAIL
Error: Process completed with exit code 1.

[amyreese]

Not sure if this is related to #7

[thatch]

No, this is probably different. Pessimist opens the project-under-test (ufmt here) METADATA file as text, using the default system encoding. None of the PEPs (241, 314, 345) specifies what the encoding should be. I suppose UTF-8 is a better default than "system-dependent"...

https://github.com/python-packaging/pessimist/blob/main/pessimist/util.py#L61