Re: [gentoo-user] Problem merging meson with setuptools. Requesting setuptools-45

[Marc Joliet]

Am Freitag, 14. Februar 2020, 15:15:06 CET schrieb Gerion Entrup:
> Am Freitag, 14. Februar 2020, 11:53:58 CET schrieb Marc Joliet:
> > Am Donnerstag, 13. Februar 2020, 11:04:54 CET schrieb Gerion Entrup:
> > > Hi,
> >
> > Hi,
> >
> > > I have a strange emerge/update problem:
> > > ```
> > > # emerge -a1 "=meson-0.52.1::gentoo" "=setuptools-42.0.2::gentoo" -v
> > > These are the packages that would be merged, in order:
> > >
> > > Calculating dependencies... done!
> > >
> > > !!! All ebuilds that could satisfy
> > > "dev-python/setuptools[python_targets_python3_6(-)?,python_targets_pytho
> > > n3_
> > > 7(-)?,python_targets_python3_8(-)?,-python_single_target_python3_6(-),-p
> > > ytho n_single_target_python3_7(-),-python_single_target_python3_8(-)]"
> > > have been masked. !!! One of the following masked packages is required
> > > to complete your request: - dev-python/setuptools-45.2.0::gentoo
> > > (masked by:
> > > package.mask, ~amd64 keyword) /usr/portage/profiles/package.mask:
> > > # Michał Górny <mgorny@g.o> (2020-01-16)
> > > # The new version loses Python 2 support but does not introduce any real
> > > # changes.  Let's mask it to reduce the noise, and hopefully try to get
> > > # python2_7 out of default PYTHON_TARGETS first.
> > >
> > > - dev-python/setuptools-45.1.0::gentoo (masked by: package.mask, ~amd64
> > > keyword)
> > >
> > > (dependency required by "dev-util/meson-0.52.1::gentoo" [ebuild])
> > > (dependency required by "=meson-0.52.1::gentoo" [argument])
> > > For more information, see the MASKED PACKAGES section in the emerge
> > > man page or refer to the Gentoo Handbook.
> > > ```
> > >
> > > I guess, this is unwanted, especially since both packages are stable.
> > > I don't find anything in the meson ebuild that explain the dependency to
> > > setuptools 45. Did I misconfigured something?
> >
> > In order to know whether you misconfigured something, we would have to
> > know
> > how you configured it in the first place, in particular "emerge --info"
> > output and relevant entries in /etc/portage/package.use.  If you use eix,
> > then "eix - e meson" and "eix -e setuptools" would be a compact way of
> > seeing lots of information.
> >
> > Just based on what you sent, however, I could imagine a case of mismatched
> > $PYTHON_TARGETS (mainly because of the "python_targets_python3_8(-)?"
> > part),
> Hmm, yeah, of course:
> ```
> # /etc/portage/make.conf:
> PYTHON_TARGETS="python3_6 python3_7 python3_8"
> PYTHON_SINGLE_TARGET="python3_7"

Just as an aside: whatever you enable in PYTHON_SINGLE_TARGET has to be in 
PYTHON_TARGETS, too (see https://wiki.gentoo.org/wiki/Project:Python/
PYTHON_TARGETS).  I don't think that's your problem, however, since neither 
meson nor setuptools use PYTHON_SINGLE_TARGET.

> # /etc/portage/profile/use.mask
> -python_targets_python3_7
> -python_single_target_python3_7
>
> $ eix -e meson
> [I] dev-util/meson
>      Verfügbare Versionen:   0.52.1^t [M](~)0.53.0^t **9999*l^t {test
> PYTHON_TARGETS="python3_6 python3_7 python3_8"} Installierte Versionen:
> 0.52.1^t(05:08:25 21.01.2020)(-test PYTHON_TARGETS="python3_6 python3_7
> -python3_8") Startseite:             http://mesonbuild.com/
>      Beschreibung:           Open source build system
> $ eix -e setuptools
> [U] dev-python/setuptools
>      Verfügbare Versionen:   42.0.2^t 44.0.0^t [M]~45.1.0^t [M]~45.2.0^t
> {test PYTHON_TARGETS="pypy3 python2_7 python3_6 python3_7 python3_8"}
> Installierte Versionen: 42.0.2^t(03:23:26 21.01.2020)(-test
> PYTHON_TARGETS="python2_7 python3_6 python3_7 -pypy3 -python3_8")
> Startseite:             https://github.com/pypa/setuptools
> https://pypi.org/project/setuptools/ Beschreibung:           Collection of
> extensions to Distutils ```
> You are right with the issue. `python3_8` in `PYTHON_TARGETS` causes the
> problem. However, I don't understand the reason for it.
>
> In /usr/portage/profiles/arch/amd64/use.stable.mask Python 3.7 and
> Python 3.8 seems to be deactivated while
> /usr/portage/profiles/arch/amd64/use.mask enables only Python 3.8 again?

Another aside: wow, those minus signs are easy to overlook in grep output, I 
was about to reply saying how nothing unmasks it :-/ .

> However, in conclusion this seems to result in a mask for
> python_targets_python3_8. But this settings seems to be respected only
> by setuptools. This seems to be also the reason for my initial emerge
> error. emerge sees, that meson wants python3_8 but this useflag is
> masked in setuptools-42.0.2 so it tries to update it to 45.2.0.
>
> When I remove "python3_8" from my make.conf, I get this output:
> ```
> emerge -a1 "=meson-0.52.1::gentoo" "=setuptools-42.0.2::gentoo" -v
> These are the packages that would be merged, in order:
>
> Calculating dependencies... done!
> [ebuild   R    ] dev-python/setuptools-42.0.2::gentoo  USE="-test"
> PYTHON_TARGETS="python2_7 python3_6 python3_7 (-pypy3) (-python3_8)" 0 KiB
> [ebuild   R    ] dev-util/meson-0.52.1::gentoo  USE="-test"
> PYTHON_TARGETS="python3_6 python3_7 -python3_8" 0 KiB ```
>
> Why is python3_8 profile masked in setuptools by not in meson?

I don't know, to be honest.  Are you sure you don't have a stray unmask in 
package.use?  Because as you can see in my previous reply, for me it's masked 
in both.

But I just had an idea: looking at your original emerge output, I don't see 
python2_7 anywhere.  The mask entry mentions that that version is the first 
without Python 2 support, so maybe you just need to add an explicit "-
python2_7" for the dependency to be satisfiable by the earlier versions?

Personally, I just keep these settings at their default.  The important thing, 
getting rid of Python 2, is currently underway, and I don't personally care 
how new my system python is.  I do my Python development in virtualenvs, 
anyway (using conda, to be exact).

> Thanks,
> Gerion

HTH
-- 
Marc Joliet
--
"People who think they know everything really annoy those of us who know we
don't" - Bjarne Stroustrup