Re: [gentoo-dev] [PATCH 1/3] meson.eclass: use python eselect module in _meson_env_array

[William Hubbs]

On Thu, Dec 17, 2020 at 10:58:23PM +0100, Michał Górny wrote:
> On Thu, 2020-12-17 at 16:50 -0500, Mike Gilbert wrote:
> > On Thu, Dec 17, 2020 at 4:44 PM Michał Górny <mgorny@g.o>
> > wrote:
> > >
> > > On Thu, 2020-12-17 at 16:30 -0500, Mike Gilbert wrote:
> > > > Closes: https://bugs.gentoo.org/759433
> > > > Signed-off-by: Mike Gilbert <floppym@g.o>
> > > > ---
> > > >  eclass/meson.eclass | 3 ++-
> > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/eclass/meson.eclass b/eclass/meson.eclass
> > > > index 21338280df33..6296f1dd26e5 100644
> > > > --- a/eclass/meson.eclass
> > > > +++ b/eclass/meson.eclass
> > > > @@ -126,7 +126,8 @@ EOF
> > > >  #          '--unicode-16=𐐷', '--unicode-32=𐤅']
> > > >  #
> > > >  _meson_env_array() {
> > > > -       python -c "${__MESON_ARRAY_PARSER}" "$@"
> > > > +       local python="$(eselect python show)"
> > > > +       ${python} -c "${__MESON_ARRAY_PARSER}" "$@"
> > > >  }
> > > >
> > > >  # @FUNCTION: _meson_get_machine_info
> > >
> > > You're missing a BDEPEND on app-eselect/eselect-python.
> > >
> > > Also, I really don't like these workarounds.  It takes a lot of
> > > effort
> > > to figure out how to break stuff, so people stop doing awful
> > > things.
> > > It's disrespectful to my time when you invent new hacks.  Now I'll
> > > have
> > > to figure out how to change eselect-python to break it.
> >
> > Why is this such an awful thing to do?
> >
> > The code should be able to execute with any version of python
> > currently supported by Gentoo.
> >
> > Please don't assume that I'm trying to avoid a proper solution here.
> > Please suggest a better alternative if you have one.
>
> I actually liked installing the script to the system.

If we are going to install it to the system, that should not be done by
dev-util/meson; it is a gentoo-specific script, so we should probably
create a separate package for it. Also, it is debatable whether that
script should be installed in a directory that is on the path.

I have major concerns about the native-symlinks use flag for python-exec.
It looks like turning this flag off would result in /usr/bin/python not being
installed which will cause massive breakage. This is similar to removing
/bin/sh., so I am strongly against the idea of this use flag unless
upstream python is recommending it. If they are not installing
/usr/bin/python in their native builds any longer, I'll be quiet.
Otherwise, imo this is a really bad idea for a use flag.

William