Changes/Disable Python 2 Dist RPM Generators and Freeze Python 2 Macros

Remove Python2 RPM Macros

Summary

The python2-rpm-macros package (containing /usr/lib/rpm/macros.d/macros.python2) will be removed from Fedora 34 and newer. The python2 RPM macros will ceases to exist. Python 2 packages are already not allowed. Around a dozen of packages use the macros in Fedora and will need to be adjusted either by expanding them or by no longer using Python 2. The python2.7dist() and python2dist() automatic provides/requires will no longer be automatically generated.

Owner

• Name: Miro Hrončok
• Email: mhroncok@redhat.com

Current status

• Targeted release: Fedora 34
• Last updated: 2021-01-14
• FESCo issue: <will be assigned by the Wrangler>
• Tracker bug: <will be assigned by the Wrangler>
• Release notes tracker: <will be assigned by the Wrangler>

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 pythn2 RPM macros from the python2-rpm-macros package (located at /usr/lib/rpm/macros.d/macros.python2) and hence decided to remove the package. The following macros will be undefined:

%{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

The following macros will remain defined 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 Python 2 section of Python packaging guidelines will be removed.

python2.7 will no longer require python2-rpm-macros and python3-rpm-generators.

Provides/requires like this will no longer be automatically generated:

python2dist(...)
python2.7dist(...)

The changes will happen after the Fedora 34 mass rebuild and before branching.

Packages that used to use those macros in Fedora will need to be adapted to expand the macros or switch to Python 3. In January 2021, we have:

• several Python 2 trac plugins, but trac uses Python 3 now
  • only those require python2dist(...)
• several Python 2 sugar packages, but they already don't build or install as sugar uses Python 3 now
• 14 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-numpy (requires python2.7dist(setuptools))
  • 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.

The removed macros and migration plan:

%{python2_sitelib}

Affected Fedora packages:

• avahi
• NFStest
• offlineimap
• python2-dns
• python2-setuptools
• python-six

Migration plan if not possible to switch to Python 3 / retire: Use %{_prefix}/lib/python2.7/site-packages.

%{python2_sitearch}

Affected Fedora packages:

• chromium
• offlineimap
• pygobject2
• pygtk2
• python2-cairo
• python2-numpy
• python-psutil

Migration plan if not possible to switch to Python 3 / retire: Use %{_libdir}/python2.7/site-packages.

%{python2_version}

Affected Fedora packages:

• offlineimap
• pygtk2
• python2-numpy
• python2-setuptools

Migration plan if not possible to switch to Python 3 / retire: Use 2.7.

%{python2_version_nodots}

No affected Fedora packages.

Migration plan: Use 27.

%{python2_platform}

No affected Fedora packages.

Migration plan: Use a glob like linux-*.

%{py2_shbang_opts}, %{py2_shbang_opts_nodash}, %{py2_shebang_flags}, %py2_shebang_fix

Affected Fedora packages:

• gimp-layer-via-copy-cut
• gimp-resynthesizer
• offlineimap

All use pathfix.py -pni "%{__python2} %{py2_shbang_opts}" ...

Migration plan: pathfix.py -pni "%{_bindir}/python2" -kas ...

%py2_build, %py2_install

Affected Fedora packages:

• NFStest
• offlineimap
• python2-cairo
• python2-dns
• python2-setuptools
• python-psutil
• python-six

Migration plan:

%build
%set_build_flags
python2 setup.py build

%install
python2 setup.py install --skip-build --root %{buildroot}

Note: Add additional sleep 1 after/before the build if you also build for Python 3.

%py2_build_egg, %py2_build_wheel, %py2_install_egg, %py2_install_wheel

No affected Fedora packages. There are no build dependencies in Fedora to build a Python 2 wheel or install it.

Migration plan for egg: Please don't use this!

%build
%set_build_flags
python2 setup.py bdist_egg

%install
python2 -m easy_install -m --prefix %{buildroot}%{_prefix} -Z <path_to_egg>

Benefit to Fedora

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 14 packages. We want to discourage building Python 2 packages. We want to remove the package from RHEL 9 as well.

Scope

• Proposal owners:
  • Drop the macros. Disable the python2dist()/python2.7dist() dependency generators.
  • No longer require python2-rpm-macros and python3-rpm-generators from python2.7.
  • Fix packages with FESCo exceptions (except already broken trac plugins), let the other affected packages burn.

• Other developers:
  • Fix their packages by migrating to Python 3 or expanding the macros.

• Release engineering: no impact on Release Engineering is anticipated

• Policies and guidelines: the Python 2 guidelines will be obliviated

• Trademark approval: (optional) Fedora Council to apply for a trademark for Die, Python 2, Die!

• Alignment with Objectives: Not really.

Upgrade/compatibility impact

None.

How To Test

Check the macros are not defined.

Packager Experience

Intentionally horrible.

Dependencies

None.

Contingency Plan

• Contingency mechanism: If this fails, we'll introduce the macros as a separate component and orphan it.
• Contingency deadline: Beta freeze.
• Blocks release? Yes, let's not release a new Fedora version unless this is accepted.
• Blocks product? All of them.

Documentation

This page is the documentation for the affected packagers.