Hi,
Is there a reason why python3 is still on python3.11, even if python3.12 is out for 9 months now? The only valid reason I see is that python 3.12 is still in “bugfix” status, but in this case, is there a way to follow the latest release?
Thanks.
The update schedule is defined here, and explains why it is the way it is: Nixpkgs Reference Manual
You’ll see that the next release/unstable, as of 737b5cd4f2f0113727312a12b4dfceee877a88c3, already has python312 set as the python3 alias.
If you need any other specific version of python, just use the relevant python package, all non-EOL versions are packaged (but not necessarily pre-built, see the documented release schedule).
If you need help figuring out how to use said package, that depends on what exactly you’d like to use the package for.
Just as a heads-up: on nixos-unstable there may be significant regressions due to python3 -> python-3.12 that have gone unnoticed, one example is this one; it’s likely there are many more similar cases (I could imagine things like home-assistant for instance).
Not unnoticed, there were just too many to handle them all in the small group that does python-updates and staging cycles.
And home-assistant is absolutely fine. Breakages are mostly a result of a lack of upstream maintenance.
Thanks, sorry for throwing oil on the fire without a check (for home-assistant). I found a few others, like sssd for autofs (override workaround easy and is being handled), and this one for which I don’t have a solution yet.
Generally my strategy is first reverting to python-3.11 for problematic derivations case-by-case, to give us more time to solve the underlying issues , either upstream or in python land.
To bring it back to the thread topic - that is precisely the:
on NixOS stable 
Note that GitHub - cachix/nixpkgs-python: All Python versions, kept up-to-date on hourly basis using Nix. auto-updates within an hour of new Python releases.