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

[Mike Gilbert <floppym@gentoo.org>]

On Sun, Dec 20, 2020 at 2:13 PM William Hubbs <williamh@gentoo.org> wrote:
>
> 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@gentoo.org>
> > > 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@gentoo.org>
> > > > > ---
> > > > >  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 don't really want to create a separate package to install a single
file. dev-util/meson is just a convenient place to install it.

I think it is ok to install it in PATH, so long as it is unlikely to
conflict with other program names.

> 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.

The native-symlinks flag exists to break things intentionally.

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=5bd5d2f9ea331119ea681e52ccaff1bce172ac98