[Distutils] Fwd: Re: PEP 517 again

[Nick Coghlan]

On 25 August 2017 at 10:08, Daniel Holth <dholth at gmail.com> wrote:
> It would be simpler if the only requirement was to produce a correct wheel.

+1

To be clear on my current position:

* due to the introduction of NotImplementedError, I'm now OK with
explicitly out-of-tree builds being deferred to a later iteration of
the API
* I'm *not* OK with banning in-tree builds in the spec, since that's
both unnecessary and unenforceable

If a frontend really wants to ensure sdist/wheel consistency, then the
way for it to do so is to build the sdist from the source tree, and
then build the wheel from the sdist. Building a wheel directly from
the source tree should ideally give the same results as building the
sdist first, but it's explicitly OK for there to be cases where they
end up being different (such as when build_sdist would raise
NotImplementedError).

As far as build_directory goes, the spec should just leave the
question of artifact caching (or the lack thereof) up to the backend
implementations for now - if/when we decide to add explicit artifact
caching support to the API specification we can make a more informed
decision at a future date based on what the initial generation of
backends are actually doing.

Cheers,
Nick.

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