bug(build): Sapling does not install on Python 3.11

[Max Coplan]

NOTE: technically Python 3.11 is not supported (at least according to pick_python.py and the README), however on my machine /usr/local/bin/python3 is 3.11. But since we're probably going to support Python ≥ 3.11 at some point, this is still a valid issue to tackle.

steps to reproduce:

1. run make install-oss with Python 3.11
   • this can be tricky because there's no way to specify the Python version. You can hardcode it in the Makefile and/or pick_python.py

expected:
Sapling builds and installs successfully

actual:
Sapling builds fine, but installation fails due to an invalid setuptools PEP 440 version:

  File "/usr/local/lib/python3.11/site-packages/setuptools/_vendor/packaging/version.py", line 197, in __init__
    raise InvalidVersion(f"Invalid version: '{version}'")
setuptools.extern.packaging.version.InvalidVersion: Invalid version: '4.4.2-20230825-130812-08821172816a'
make: *** [install-oss] Error 1

workaround:
explicitly set the version to something unoffensive

SAPLING_VERSION=42.69 make install-oss

probable cause:
as the error message says, "4.4.2-20230825-130812-08821172816a" is not a valid version number according to PEP 440.

We either need to change the format in setup.py/pickversion or use an alternative to distutils.

[Max Coplan]

we could simply use .s instead of -s:

>>> from setuptools.extern import packaging; packaging.version.Version("4.4.2-20230825-130812-08821172816a")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.11/site-packages/setuptools/_vendor/packaging/version.py", line 197, in __init__
    raise InvalidVersion(f"Invalid version: '{version}'")
setuptools.extern.packaging.version.InvalidVersion: Invalid version: '4.4.2-20230825-130812-08821172816a'
>>> from setuptools.extern import packaging; packaging.version.Version("4.4.2.20230825.130812.08821172816a")
<Version('4.4.2.20230825.130812.8821172816a0')>

[Max Coplan]

off-topic: are we using /SAPLING_VERSION for anything?

[Adam Hupp]

I was getting this silent failure without using python 3.11, running the build installed by homebrew. I reinstalled from homebrew and it works now. Not reassuring!

[Adam Hupp]

A more informative runtime error would be nice.

[zzl]

this is fixed in 14d9251