[Distutils] command line versus python API for build system abstraction (was Re: build system abstraction PEP)

[Robert Collins]

On 12 November 2015 at 02:30, Paul Moore <p.f.moore at gmail.com> wrote:
> On 10 November 2015 at 22:44, Nathaniel Smith <njs at pobox.com> wrote:
>> "Stdin is unspecified, and stdout/stderr can be used for printing
>> status messages, errors, etc. just like you're used to from every
>> other build system in the world."
>
> This is over simplistic.
>
> We have real-world requirements from users of pip that they *don't*
> want to see all of the progress that the various build tools invoke.
> That is not something we can ignore. We also have some users saying
> they want access to all of the build tool output. And we also have a
> requirement for progress reporting.
>
> Taking all of those requirements into account, pip *has* to have some
> level of control over the output of a build tool - with setuptools at
> the moment, we have no such control (other than "we may or may not
> show the output to the user") and that means we struggle to
> realistically satisfy all of the conflicting requirements we have.
>
> So we do need much better defined contracts over stdin, stdout and
> stderr, and return codes. This is true whether or not the build system
> is invoked via a Python API or a CLI.

Aye.

I'd like everyone to take a breather on this thread btw. I'm focusing
on the dependency specification PEP and until thats at the point I
can't move it forward, I won't be updating the draft build abstraction
PEP: when thats done, with the thing Donald and I hammered out on IRC
a few days back (Option 3, earlier) then we'll have something to talk
about and consider.

-Rob

-- 
Robert Collins <rbtcollins at hp.com>
Distinguished Technologist
HP Converged Cloud