[Distutils] Finishing up PEP 517

[Nick Coghlan]

On 28 June 2017 at 14:25, Nathaniel Smith <njs at pobox.com> wrote:
> pyproject.toml is just an example anyway; get_build_wheel_requires
> runs arbitrary code, and that code could potentially return different
> results in different trees.

No, I don't want to give backends permission to work that way. If a
frontend runs get_build_wheel_requires() against the VCS tree, then
that should also be sufficient to set up an environment to build an
unpacked sdist - the backend isn't permitted to require that both
hooks be run against the exact same tree. (It's fine if it returns
some extra dependencies that may not technically be needed for a
from-sdist build, though)

To put it another way, if the "VCS-tree-for-build-requirements,
unpacked-sdist-tree for build" combination doesn't work, that's a bug
in the backend, not a bug in the frontend.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia