[Distutils] Fwd: Re: PEP 517 again

Nick Coghlan ncoghlan at gmail.com
Fri Aug 25 08:29:51 EDT 2017

On 25 August 2017 at 17:47, Paul Moore <p.f.moore at gmail.com> wrote:
> If anyone feels that it's *not* reasonable for users to expect "build
> a wheel" and "build a sdist and build a wheel from that" to produce
> the same results for a given source tree (assuming the backend
> supports both building wheels and sdists from the given source tree)
> then they need to speak up with a *specific* example of a use case, so
> we can include it in the PEP as a motivating example, and use it in
> future debates.

Just the NotImplementedError case: running build_wheel against a
source tree is permitted to succeed in cases where build_sdist raises
NotImplementedError, and in these cases, the result may *not* match
what you would have gotten if the necessary inputs and tools for
creating the sdist were available.

> At the moment too much discussion is getting bogged
> down with comments like "I think someone said that XXX needs this..."
> I'm *not* interested in trying to tie down "the correct behaviour" any
> more tightly than this.

Cool, we're on the same page then - the specific thing that was
bothering me was the request to start articulating "permitted side
effects" at the PEP level, and I don't think the PEP is the right
place for that.


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

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