8:43 a.m.
This proposal has been heavily modified:
https://fedoraproject.org/w/index.php?title=Changes%2FDisable_Python_2_Di...
It has therefore been resubmitted.
https://fedoraproject.org/wiki/Changes/Disable_Python_2_Dist_RPM_Generato...
= Disable Python 2 Dist RPM Generators and Freeze Python 2 Macros =
== Summary ==
The `python2.7dist()` and `python2dist()` automatic provides/requires
from {{package|python-rpm-generators}} will no longer be automatically
generated, no functional packages in Fedora use them. The `python(abi)
= 2.7` automatic provides/requires will be kept.
The {{package|python2-rpm-macros}} package will be removed from Fedora
34 and newer. The python2 RPM macros
(`/usr/lib/rpm/macros.d/macros.python2`) will be moved to
{{package|python2.7}} and frozen (no new development, except critical
bugfixes that affect packages outside the remaining Python 2
ecosystem).
Note that Python 2 packages are already not allowed in Fedora, except
explicitly granted exceptions.
== Owner ==
* Name: [[User:Churchyard|Miro Hrončok]]
* Email: mhroncok(a)redhat.com
== Detailed Description ==
Python 2 is upstream dead, usage in Fedora packages is forbidden,
except for several package with an explicit FESCo approved exception.
The Python Maintenance team no longer wishes to support the python2
dist RPM generators from the {{package|python-rpm-generators}} package
nor the python2 RPM macros from the {{package|python2-rpm-macros}}
package (located at `/usr/lib/rpm/macros.d/macros.python2`) and hence
decided to disable the generators for Python 2 and freeze the macros.
Provides/requires like this will no longer be automatically generated in Fedora:
python2dist(...)
python2.7dist(...)
Currently, no functional Fedora 34 packages need such provides. The
`python(abi) = 2.7` automatic provides/requires will be kept.
The following macro definitions will be moved from
{{package|python2-rpm-macros}} to {{package|python2.7}}:
%{python2_sitelib}
%{python2_sitearch}
%{python2_version}
%{python2_version_nodots}
%{python2_platform}
%{py2_shbang_opts}
%{py2_shbang_opts_nodash}
%{py2_shebang_flags}
%py2_shebang_fix
%py2_build
%py2_build_egg
%py2_build_wheel
%py2_install
%py2_install_egg
%py2_install_wheel
And their definition will remain frozen unless a bug is found that
affects Fedora packages outside the remaining Python 2 ecosystem.
Packagers of Python 2 packages affected by bugs in the macros are
encouraged to apply workarounds and/or submit fixes themselves.
Only the following packages use some of the macros:
* several Python 2 trac plugins, but {{package|trac}} uses Python 3 now
** only those require `python2dist(...)` / `python2.7dist(...)`
* several Python 2 sugar packages, but they already don't build and/or
install as {{package|sugar}} uses Python 3 now
* 13 other affected packages in Fedora (some of them co-owned by Python Maint):
** avahi
** gimp-layer-via-copy-cut
** gimp-resynthesizer
** chromium
** NFStest
** offlineimap
** pygobject2
** pygtk2
** python-psutil
** python-six
** python2-cairo
** python2-dns
** python2-setuptools
Note: Many other packages use the macros in a disabled `%if` section.
Some of the listed ones might as well (and hence are not really
impacted), the list is an intersection of packages that (Build)Require
Python 2 and are greppable for the macros.
{{package|python2.7}} will provide and obsolete
{{package|python2-rpm-macros}} at least for 2 more releases (or until
it is removed entirely from Fedora).
The following macros will remain defined in
{{package|python-srpm-macros}} for the time being to not break
packages that are using Python 2 as build-time only dependency (which
is also not allowed, but happens more often):
%{__python2}
%{python2}
The
[https://docs.fedoraproject.org/en-US/packaging-guidelines/Python_Appendix...
Python 2 section of Python packaging guidelines] will be amended to
say that the Python 2 macros may not completely mirror the Python 3
macros.
The changes will happen after the Fedora 34 mass rebuild and before branching.
== Feedback ==
At first, we have
[https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.o...
proposed to remove the macros entirely]. That proposal has received
negative feedback and we have reworked it to only freeze the macros
and disable the dist generators.
== Benefit to Fedora ==
With each change of the RPM Python dist generators we had to create
artificial packages to test the impact on Python 2, because the real
set of Python 2 package in Fedora is basically non-existent. By
disabling them, we no longer have to worry about breaking things for
our downstreams or projects building atop Fedora.
In the past, we tried to keep the macros as similar to their Python 3
counterparts as possible, but we have decided that it is not worth it
for 13 packages. This way, historical packages can still be built atop
Fedora with the macros, but we don't need to worry about keeping them
up-to-date. Once {{package|python2.7}} is retired, the macros will go
away as well. This is also true for RHEL 9.
== Scope ==
* Proposal owners:
** Disable the `python2dist()`/`python2.7dist()` dependency generators.
** Move the python2 macros from {{package|python2-rpm-macros}} to
{{package|python2.7}}.
** Remove {{package|python2-rpm-macros}} and obsolete/provide it from
{{package|python2.7}}.
* Other developers: No action required.
* Release engineering: no impact on Release Engineering is anticipated
* Policies and guidelines: a note will be added to the Python 2 guidelines
* Trademark approval: Not necessary.
* Alignment with Objectives: Not really.
== Upgrade/compatibility impact ==
The {{package|python2-rpm-macros}} package will be obsoleted by
{{package|python2.7}}. Users that happened to have the macros
installed but not the interpreter will suddenly pull the interpreter
on upgrades, but we think that's a reasonable compromise.
== How To Test ==
Build a Python 2 package that used to provide and/or require
`python2.7dist()` or `python2dist()` automatically. Verify it does not
do that. Verify it still requires `python(abi) = 2.7`. Verify the
macros are still defined. Verify {{package|python2-rpm-macros}} is no
more. Verify {{package|python2.7}} does not depend on RPM.
== Packager Experience ==
Mildly worse for packagers building Python 2 RPMs atop Fedora. If such
packagers need the dist generators to do so, they are encouraged to
build their own version. Feel free to talk to the change owner about
how to do that.
Fedora packages are not affected.
== Dependencies ==
None.
== Contingency Plan ==
* Contingency mechanism: Revert the changes.
* Contingency deadline: Beta freeze.
* Blocks release? No.
* Blocks product? No.
== Documentation ==
This page is the documentation for the affected 3rd party packagers.
--
Ben Cotton
He / Him / His
Senior Program Manager, Fedora & CentOS Stream
Red Hat
TZ=America/Indiana/Indianapolis