Fixing missing dependency preventing it to be installed

[havietisov]

buildtools is actually required for this to be installed. In environments that don't have buildtools, following error is encountered :
#2 (comment)

[tridao]

Thanks @havietisov!

[prescod]

I am skeptical about the pull request. It changes line 258 of setup.py, but the crash happens when Python tries to run lines 8, 11 and 18.

Instead, I made a pyproject.toml with this content:

[build-system]
requires = ["packaging", "torch", "setuptools", "wheel"]

This seems to install the four requirements before running setup.py.

[havietisov]

I just tried it and yes, @prescod, you're correct, it doesn't work when packaging is not installed.
My request was motivated by shenanigans caused by missing "buildtools" due to which, somehow, this thing complained about missing "packaging" in environments, when "packaging" was present.