[Distutils] PEP 517 - specifying build system in pyproject.toml

[Paul Moore]

On 19 May 2017 at 16:16, Thomas Kluyver <thomas at kluyver.me.uk> wrote:
> On Fri, May 19, 2017, at 03:41 PM, Paul Moore wrote:
>> Can we specify what encoding the informational text must be written
>> in?
>
> Sure, that makes sense. What about:
>
> All hooks are run with working directory set to the root of the source
> tree, and MAY print arbitrary informational text on stdout and stderr.
> This text SHOULD be UTF-8 encoded, but as building may invoke other
> processes, install tools MUST NOT fail if the data they receive is not
> valid UTF-8; though in this case the display of the output may be
> corrupted.

Looks good, although whether UTF-8 is viable on Windows is something
I'll have to think about.

> Do we also want to recommend that install tools set
> PYTHONIOENCODING=utf-8 when invoking build tools? Or leave this up to
> the build tools?

Good question. At the moment, the only 2 cases I know of are
setuptools/distutils and flit. For setuptools, I'm pretty sure there's
no handling of subprocesses, it just fires them off and lets them
write to the console - so there's nothing to even ensure a consistent
encoding. We may have to allow for special casing with setuptools, as
I doubt anyone's going to put in the effort to add a transcoding layer
in there.

For flit, would having the install tool set PYTHONIOENCODING help?

I don't know immediately what I'd do if I were designing a brand new
build tool that called out to a 3rd party compiler. Let me think about
it.
Paul