Re: Should python-build-system packages have native-inputs?

[Hartmut Goebel]

Am 28.04.2018 um 08:50 schrieb Chris Marusich:
> * Should we change these native-inputs to inputs to prevent confusion?
>   I can personally vouch for the fact that the presence of native-inputs
>   in python-build-system packages confused the heck out of me at first!
 
As Fis already wrote:  These native-inputs are for testing and shouldn't
be installed in normal case. Please see "Python Modules" in the manual:

Python packages required only at build time---e.g., those listed with
the @code{setup_requires} keyword in @file{setup.py}---or only for
testing---e.g., those in @code{tests_require}---go into
@code{native-inputs}.  The rationale is that (1) they do not need to be
propagated because they are not needed at run time, and (2) in a
cross-compilation context, it's the ``native'' input that we'd want.

> * Are there any circumstances under which it actually WOULD make sense
>   to cross-compile a Python package?

Of course: Pure-python packages should be able to be cross-compiled
without any problems, sicne the bytes-code is the same for all
platforms. And for extension modules it would allow compiling on a
faster environment (e.g. x86 vs. ARMv4).

(I was not aware of python packages are not cross-compiled, thus I can
only guess the reason why this is not possible: Python distutils may not
be able to *cross*-compile extension modules. Maybe we could work on this.)

-- 
Regards
Hartmut Goebel

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