Summary
setup.py reads README.md without specifying an encoding, so Python falls back to the locale encoding. On Windows that is cp1252, which cannot decode the UTF-8 emoji in the README. This aborts metadata generation, so installing or building the package fails on Windows.
Linux and macOS are unaffected, because their locale encoding is already UTF-8.
Error
Traceback (most recent call last):
...
File "<string>", line 11, in <module>
File "...\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 0x8f in position 969: character maps to <undefined>
error: subprocess-exited-with-error
Preparing metadata (pyproject.toml) did not run successfully.
Summary
setup.pyreadsREADME.mdwithout specifying an encoding, so Python falls back to the locale encoding. On Windows that is cp1252, which cannot decode the UTF-8 emoji in the README. This aborts metadata generation, so installing or building the package fails on Windows.Linux and macOS are unaffected, because their locale encoding is already UTF-8.
Error