On Tue, Jun 27, 2017 at 9:20 PM, Nick Coghlan <ncoghlan@gmail.com> wrote:
On 28 June 2017 at 13:43, Nathaniel Smith <njs@pobox.com> wrote:
On Tue, Jun 27, 2017 at 4:20 AM, Nick Coghlan <ncoghlan@gmail.com> wrote:
On 27 June 2017 at 18:54, Nathaniel Smith <njs@pobox.com> wrote:
On Tue, Jun 27, 2017 at 12:27 AM, Nick Coghlan <ncoghlan@gmail.com> wrote:
2. If you don't find the input preparation hook:
- call `get_build_sdist_requires()` - call `get_build_wheel_requires()` - install both sets of additional dependencies - call `build_sdist()` - unpack the sdist into the build directory - call `build_wheel()`
Side note: I think this is wrong -- I think you can't call get_build_wheel_requires until after you've unpacked the sdist, because that's a whole new tree that might be arbitrarily different. (In practice I guess this should never happen, but we should be clear conceptually I think.)
No, both `get_build_wheel_requires()` and `build_wheel()` also have to work in-place - backends aren't allowed to assume that *all* builds will be out-of-tree, even though pip specifically is expected to work that way. Neither of these hooks is allowed to give different results depending on whether you're doing an in-place or out-of-tree build.
Right. But if you're building and sdist and unpacking it and then calling build_wheel there, then that's not an out-of-tree build, it's an in-tree build in a new tree. The wheel hooks are certainly allowed to give different results in a VCS-tree and an unpacked-sdist-tree, they have different pyproject.toml files!
Umm, no. The pyproject.toml file MUST NOT change when building the sdist. It's a human-managed input file - if any step of the build process mutates it, that step is *broken*.
I agree that changing the pyproject.toml file is a terrible idea in most cases I still think we should do the "right thing" when it happens, where "right" means "doesn't involve complex underspecified coupling between conceptually distinct phases", because this thing needs to fit in people's brains. It's not so much that pyproject.toml changing is an important case, as that if we can even *tell* whether it changed then there's something wrong with our architecture. 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. -n -- Nathaniel J. Smith -- https://vorpus.org