On Sat, Jun 3, 2017 at 8:59 PM, Paul Moore <p.f.moore@gmail.com> wrote:
On 3 June 2017 at 03:14, Nathaniel Smith <njs@pobox.com> wrote:
> So far my belief is that packages with expensive build processes are
> going to ignore you and implement, ship, document, and recommend the
> direct source-tree->wheel path for developer builds. You can force the
> make-a-wheel-from-a-directory-without-copying-and-then-install-it
> command have a name that doesn't start with "pip", but it's still
> going to exist and be used. Why wouldn't it? It's trivial to implement
> and it works, and I haven't heard any alternative proposals that have
> either of those properties. [1]

I may be misunderstanding you, but it's deeply concerning if you're
saying "as a potential backend developer, I'm sitting here listening
to the discussion about PEP 517 and I've decided not to raise my
concerns but simply to let it be implemented and then ignore it".

I think you partly misunderstood - "ignore you" should mean "ignore pip" or "ignore the mandatory sdist part of PEP 517" not "ignore all of PEP 517". And concerns have been raised (just rejected as less important than the possibility of more bug reports to pip)?

And I agree with Nathaniel's view in the paragraph above.
OTOH, I'm not sure how you plan on ignoring it - are you suggesting
that projects like numpy won't support "pip install numpy" except for
wheel installs[1]?

Of course not, that will always be supported. It's just that where the developer/build docs now say "python setup.py ..." we want them to say "pip install . -v" and with sdist generation that won't happen - they will instead say "somenewtool install ." where somenewtool is a utility that does something like:
1. invoke backend directly to build a wheel (using PEP 517 build_wheel interface)
2. install the wheel with pip
and probably also
1. invoke backend directly for in-place build
2. make the inplace build visible (may involve telling pip to uninstall the project if it's installed elsewhere, and messing with PYTHONPATH or pip metadata)