Python package maintenance
Support for Python 2
Since Python 2.7 reached EOL, Gentoo is currently phasing out support for Python 2. Unless your package or its reverse dependencies really need it, you should omit it from PYTHON_COMPAT. If you're adding a new package and it does not support Python 3, do not add it.
Many upstreams are removing Python 2 support from new releases of their software. We remove it proactively whenever reverse dependencies permit in order to anticipate this and avoid having to deal with lots of reverse dependencies afterwards.
Packages that do not support Python 3 and are unlikely to start supporting it soon are being slowly removed.
Which implementations to test new packages for?
The absolute minimum set of targets are the current default targets found in profiles/base/make.defaults. However, developers are strongly encouraged to test at least the next Python 3 version in order to ease future transition, and preferably all future versions.
Marking for PyPy3 is optional. At this moment, we do not aim for wide coverage of PyPy3 support.
Adding new Python implementations to existing packages
New Python implementations can generally be added to existing packages without a revision bump. This is because the new dependencies are added conditionally to new USE flags. Since the existing users can not have the new flags enabled, the dependencies do not need to be proactively added to existing installations.
This usually applies to stable packages as well as new Python targets are generally use.stable.mask-ed. This means that stable users will not be able to enable newly added flags and therefore the risk of the change breaking stable systems is minimal.
Which packages can be (co-)maintained by the Python project?
A large part of the Python ecosystem is fairly consistent, making it feasible for (co-)maintenance by the Gentoo Python team.
As a rule of thumb, Python team is ready to maintain packages specific to the Python ecosystem and useful for the general population of Python programmers. This includes Python interpreters and tooling, packages purely providing Python modules and extensions and utilities specific to the Python language.
However, the Python team has limited manpower, therefore it may reject packages that have high maintenance requirements. As a rule, Python team does not accept packages without working tests.
If your package matches the above profile, feel free to ask a member of the Python project whether they would like to (co-)maintain the package. However, if you are not a member of the project, please do not add us without asking first.
Porting packages to a new EAPI
When porting packages to a new EAPI, please take care not to port the dependencies of Portage prematurely. This generally includes app-portage/gemato, dev-python/setuptools and their recursive dependencies.
Ideally, these ebuilds carry an appropriate note above their EAPI line, e.g.:
# please keep this ebuild at EAPI 7 -- sys-apps/portage dep EAPI=7
This does not apply to test dependencies — they are not strictly necessary to install a new Portage version.