Re: [PATCH v2 3/3] gnu: Add python2-wxpython.

[Leo Famulari <leo@famulari.name>]

On Tue, Oct 25, 2016 at 08:13:55PM +0300, Theodoros Foradis wrote:
> Leo Famulari writes:
> >> +    (native-inputs
> >> +     `(("gtk+" ,gtk+-2)
> >> +       ("expat" ,expat)
> >> +       ("libjpeg" ,libjpeg)
> >> +       ("libpng" ,libpng)
> >> +       ("libtiff" ,libtiff)
> >> +       ("libsm" ,libsm)
> >> +       ("libx11" ,libx11)
> >> +       ("mesa" ,mesa)
> >> +       ("pkg-config" ,pkg-config)
> >> +       ("python2-setuptools" ,python2-setuptools)
> >> +       ("zlib" ,zlib)))
> >
> > To clarify, all these native-inputs are only used while building?
> > Native inputs typically are not intended to be available once the
> > package has been built and installed.
> 
> To quote Danny Milosavljevic, whose original patch of python2-wxpython I
> modified:
> > I added gtk, opengl etc as native inputs instead of regular inputs
> > because from the point of view of Python they are not direct inputs.

I'm not sure what that means in this case.

> I guess this applies to gtk+,opengl,mesa and expat(?) (the others are
> intented to be native-inputs for sure). I am unsure if they are intended
> to be available at runtime. I assumed they were not, based on the
> previous comment. If they, they should be moved to inputs.

I checked the references of the built package like this:

$ guix gc --references $(./pre-inst-env guix build python2-wxpython)
/gnu/store/1xfc2pwr7qfjib9kfy3n2hjq56z7jyjx-python-2.7.11
/gnu/store/6njycb0nzbczqbzvcyn1vw5sg7xsaanr-python2-setuptools-18.3.1
/gnu/store/9nifwk709wajpyfwa0jzaa3p6mf10vxs-gcc-4.9.3-lib
/gnu/store/a5xcl27fflh6ppysf5wrsfnn3ly2gyhy-python2-wxpython-3.0.2.0
/gnu/store/fdlind5y49q37m1g1wsvx840q2scrp6x-wxwidgets-gtk2-3.0.2
/gnu/store/m9vxvhdj691bq1f85lpflvnhcvrdilih-glibc-2.23
/gnu/store/ykzwykkvr2c80rw4l1qh3mvfdkl7jibi-bash-4.3.42

As you can see, many of the package's inputs not referred to by the
built package. This means that those inputs will by deleted by the next
`guix gc` (unless some other installed package refers to them). That's
fine for native-inputs, which are supposed to be used only while
building.

As for whether or not the packages are required at run-time, I don't
know. wxPython's documentation should explain what the software does and
what libraries it wants to use.

Hartmut, assuming that wxPython needs these packages at run-time, do you
have any recommendations for how to keep references to them? I ask based
on your recent work on Python packaging.

Otherwise this package looks good, minus some minor cosmetic nits.