commit: bf718a7c9761e42e51c9deaa6a1fe7241be4c04a Author: Michał Górny <mgorny <AT> gentoo <DOT> org> AuthorDate: Fri Mar 31 17:15:15 2023 +0000 Commit: Michał Górny <mgorny <AT> gentoo <DOT> org> CommitDate: Sun Apr 2 15:11:49 2023 +0000 URL: https://gitweb.gentoo.org/data/gentoo-news.git/commit/?id=bf718a7c
2023-04-01-python3-11: add news item Signed-off-by: Michał Górny <mgorny <AT> gentoo.org> 2023-04-02-python3-11/2023-04-02-python3-11.en.txt | 125 +++++++++++++++++++++ 1 file changed, 125 insertions(+) diff --git a/2023-04-02-python3-11/2023-04-02-python3-11.en.txt b/2023-04-02-python3-11/2023-04-02-python3-11.en.txt new file mode 100644 index 0000000..cf24ef1 --- /dev/null +++ b/2023-04-02-python3-11/2023-04-02-python3-11.en.txt @@ -0,0 +1,125 @@ +Title: Python 3.11 to become the default on 2023-05-01 +Author: Michał Górny <mgo...@gentoo.org> +Posted: 2023-04-02 +Revision: 1 +News-Item-Format: 2.0 +Display-If-Installed: dev-lang/python:3.9 +Display-If-Installed: dev-lang/python:3.10 + +We are planning to switch the default Python target of Gentoo systems +on 2023-05-01, from Python 3.10 to Python 3.11. If you have not changed +the values of PYTHON_TARGETS or PYTHON_SINGLE_TARGET, the change will +have immediate effect on your system and the package manager will try +to switch automatically on the next upgrade following the change. + +If you did change the values, prefer a safer approach or have problems +with the update, read on. + +Please note that the default upgrade method switches packages to the new +Python versions as they are rebuilt. This means that all interdependent +packages have to support the new version for the upgrade to proceed, +and that some programs may temporarily fail to find their dependencies +throughout the upgrade (although programs that are already started +are unlikely to be affected). + +At the same time, the support for Python 3.9 target will be removed +from the eclasses. The interpreter package will remain supported +for as long as feasible though. PyPy3.9 will remain supported until +PyPy3.10 comes out and becomes stable. + + +If you have PYTHON_TARGETS or PYTHON_SINGLE_TARGET declared +in make.conf, please remove these declarations as they will interfere +with the package.use samples provided below. Using make.conf for Python +targets is discouraged as it prevents package defaults from applying +when necessary. This news item assumes using /etc/portage/package.use +or your package manager's equivalent file for configuration. + + +At this point, you have a few configuration options to choose from: + +1. If you wish Python upgrades to apply automatically, you can remove + PYTHON_TARGETS and PYTHON_SINGLE_TARGET declarations. When + the defaults change, your package manager should handle the upgrade + automatically. However, you may still need to run the update + commands if any problems arise. + +2. If you wish to defer the upgrade for the time being, you can + explicitly set the old values in package.use. + +3. If you wish to force the upgrade earlier, you can explicitly set + the new values and run the upgrade commands. + +4. If you wish to use a safer approach (i.e. less likely to temporarily + break packages during the upgrade), you can perform a multi-step + upgrade as outlined below. + +5. Finally, you can use an arbitrary combination of PYTHON_TARGETS + and PYTHON_SINGLE_TARGET. + + +Deferring the upgrade +===================== +To defer the upgrade, explicitly set the old targets: + + */* PYTHON_TARGETS: -* python3_10 + */* PYTHON_SINGLE_TARGET: -* python3_10 + +This will enforce Python 3.10 and block any future updates. However, +please note that this is only a temporary solution and you will +eventually need to perform the migration. + + +Forcing the upgrade +=================== +To force the upgrade earlier, explicitly select the Python 3.11 targets: + + */* PYTHON_TARGETS: -* python3_11 + */* PYTHON_SINGLE_TARGET: -* python3_11 + +However, it is important to remember to remove this after the defaults +change, as it will interfere with the automatic switch to the next +Python version in the future. + + +Safer upgrade procedure +======================= +A safer approach is to add Python 3.11 support to your system first, +and only then remove Python 3.10. However, note that this involves two +rebuilds of all the affected packages, so it will take noticeably +longer. + +First, enable both Python 3.10 and Python 3.11, and then run the upgrade +commands: + + */* PYTHON_TARGETS: -* python3_10 python3_11 + */* PYTHON_SINGLE_TARGET: -* python3_10 + +Then switch PYTHON_SINGLE_TARGET and run the second batch of upgrades: + + */* PYTHON_TARGETS: -* python3_10 python3_11 + */* PYTHON_SINGLE_TARGET: -* python3_11 + +Finally, switch to the final version and upgrade: + + */* PYTHON_TARGETS: -* python3_11 + */* PYTHON_SINGLE_TARGET: -* python3_11 + +You may wish to remove the target overrides after the defaults switch. +Alternatively, you can keep them to block the next automatic upgrade +to Python 3.11, and upgrade manually then. + + +Upgrade commands +================ +The Python 3.10 cleanup requires that Python 3.10 is removed from +the complete dependency trees in batch. If some of the +installed packages using an older Python version are not triaged +for the upgrade, the package manager will throw dependency conflicts. +This makes it important that the upgrade is carried via a --deep +--changed-use @world upgrade, as well as that any stray packages +are removed prior to it, e.g.: + + emerge --depclean + emerge -1vUD @world + emerge --depclean
