Clarification on string arguments in PEP 517 hooks

I'm in the process of implementing PEP 517 for pip, and I've hit a
question. I'm pretty sure I know the answer, but I want to be clear,
as whatever the answer is will require some fixing up.

The various hooks take directory paths as arguments, and typically
return a filename (e.g., build_wheel). The returned filename is always
explicitly noted as being *a unicode string*. However, argumnents
(metadata_directory in build_wheel/prepare_metadata_for_build_wheel)
are *not* explicitly mandated to be Unicode.

My assumption is that the intent is that *all* strings, whether
arguments or return values, must be Unicode.

The reason that I've hit this is that the current setuptools PEP 517
backend passes the metadata_directory direct to distutils which, on
Python 2, checks for a (non-Unicode) string type and errors if Unicode
is supplied. Fixing that is going to be annoyingly tricky, so I want
to be sure that's the requirement before I start making fixes to
setuptools.

Paul
--
Distutils-SIG mailing list -- [email protected]
To unsubscribe send an email to [email protected]
https://mail.python.org/mm3/mailman3/lists/distutils-sig.python.org/
Message archived at https://mail.python.org/mm3/archives/list/[email protected]/message/WW44ZRHKD3VDDEWODBPRPZWWENVJNGW5/