Re: [gentoo-dev] [RFC] Splitting dev-lang/python into per-slot packages, starting with 3.14

[orbea <orbea@riseup.net>]

On Sat, 12 Oct 2024 10:12:56 +0200
Michał Górny <mgorny@gentoo.org> wrote:

> Hello,
> 
> Historically, all versions of CPython were slotted in a single
> package, i.e.:
> 
>   dev-lang/python:3.N
> 
> This approach has been causing a major annoyance for users -- due to
> Portage "greedy" upgrade behavior, any time a new Python version was
> keyworded, Portage insisted on installing it, even though user's
> selected targets did not request the specific version.  The
> potentially worst consequence of that would be random user scripts
> stopping to work, as they suddenly start using new Python, while all
> their dependencies are still installed per PYTHON_TARGETS.
> 
> Upstream has recently added freethreading support to CPython.  Since
> this support is not ABI compatible with the regular build, we need to
> introduce a separate target for it, and to package it separately.
> In the planned patchset, I've already put it as a separate package
> (dev- lang/python-freethreading), because otherwise Portage would
> insist on upgrading to it!
> 
> However, I think the cleanest way forward would be to stop slotting
> CPython like this, and instead have a separate package for each
> version, just like the vast majority of distributions do, i.e.:
> 
>   dev-lang/python3_N
> 
> This naturally means that only the specific version requested (e.g.
> via targets) would be installed, and no cross-slot autoupgrades would
> happen.  Ideally, I'd like to start doing that with Python 3.14 whose
> first alpha is expected next week.  Depending on how they handle
> freethreading, we'd end up having the first or both of:
> 
>   dev-lang/python3_14
>   dev-lang/python3_14t
> 
> (Alternatives: python-3_14, python-freethreading-3_14? Though I think
> following PYTHON_TARGETS is cleaner here.)
> 
> As a side notice, the existing versions would probably remain as-is
> until removal, since there's really no gain in splitting them, given
> we'd have to retain compatibility with existing depstrings.
> 
> Comments?
> 

Would you be willing to carry the LibreSSL patches in tree if you do
this? Its already a serious chore keeping the python ebuilds in sync
with ::gentoo and if you start to double the versions that will only be
more ridiculous.