Bug 662422

Summary:	Default python should be changed automatically
Product:	Gentoo Linux	Reporter:	Dirkjan Ochtman (RETIRED) <djc>
Component:	Current packages	Assignee:	Python Gentoo Team <python>
Status:	RESOLVED OBSOLETE
Severity:	normal	CC:	mgorny, ostroffjh
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---

Description Dirkjan Ochtman (RETIRED) gentoo-dev

2018-07-29 14:05:10 UTC

I have a mostly-stable system with no explicit PYTHON_TARGETS. Over the weekend, I emerged world with --changed-use. Since uninstalled all libraries for the default Python (3.5) and reinstalled them for Python 3.6. After this, all my cron jobs started failing because of missing libraries.

This seems like a suboptimal way of handling these upgrades.

Comment 1 Mike Gilbert gentoo-dev

2018-07-29 16:25:16 UTC

Do you have a proposal for how this could be handled better? I'm not sure how we could figure out what the user actually wants.

Comment 2 Mike Gilbert gentoo-dev

2018-07-29 16:29:10 UTC

I think this is only an issue for scripts written/managed outside of portage.

Scripts that are installed using an ebuild would be installed in /usr/lib/python-exec/${EPYTHON}/, and the /usr/bin/python-exec wrapper will iterate over all installed python versions until it finds one that is valid for the script being executed.

Comment 3 Michał Górny archtester

2018-07-29 16:59:31 UTC

This should happen if you leave python-exec.conf blank.

Comment 4 Dirkjan Ochtman (RETIRED) gentoo-dev

2018-07-29 19:11:16 UTC

If a new version of Python is installed because it is now in PYTHON_TARGETS and there are no other versions of Python (of the same major version -- I'm guessing this won't be exercised anytime soon if ever for anything other than 3.x) in PYTHON_TARGETS, then the new version should become the default as soon as it is installed. That probably still leaves a short window where it doesn't have libraries installed, but it definitely seems better than the current process.

And yes, I'm not talking about Portage-managed scripts; I have many little utility things that do things like scraping feeds or testing API availability.

Comment 5 Mike Gilbert gentoo-dev

2018-07-29 20:01:34 UTC

Maybe we could write a small ebuild that would have all python versions in PYTHON_COMPAT, and would simply make sure that the currently selected system python version is enabled in PYTHON_TARGETS.

Comment 6 Jack 2023-05-01 15:51:14 UTC

I'm curious if this is still relevant after the switch to python3_11 as default.

Comment 7 Sam James archtester

2023-05-01 15:52:03 UTC

(In reply to Jack from comment #6)
> I'm curious if this is still relevant after the switch to python3_11 as
> default.

I don't think so, especially given the python-exec change we made a few years ago to make "Python targets follow it" when we deprecated eselect-python.