Michał Górny <mgo...@gentoo.org> writes: > Hello, > > Historically, all versions of CPython were slotted in a single package, > i.e.: > > dev-lang/python:3.N >
I feel like this whole thing happened so fast I didn't have a chance to comment properly. I understand you've retracted it but I'd like to add some context and background and so on for future reference anyway. > 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. > This is bug #702806 which happens with python-any-r1 which has an any-of dependency on dev-lang/python. That's why we don't see it with e.g. Qt. It's a bit annoying but not terrible. > 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! > It wouldn't! See above. It would, however, if we made it eligible for python-any-r1, but to be honest, I think we should exclude the freethreaded build from that. It's all risk (and/or downsides) with no real gain, as I don't expect a whole-freethreaded system is going to be possible any time soon anyway. > 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 > As others have noted, such a proposal needs specific arguments as to why SLOTs aren't a good fit. I agree with you that they're not always a good fit -- SQLite and libxml2 are good examples you gave downthread, but the onus is on the one making the proposal. Now, for Python, there's a few disadvantages: * losing the ordering on PV for e.g. has_version (we could add a helper in python-utils-r1 for this); * losing the ability to consistently set package.use/package.env for all Pythons, like always enabling PGO or tests; * disruption to scripts which have reasonably assumed we'd always have a dev-lang/python (we'd need to do something like we have planned for pkgmoves, I think -- make Portage know about it and suggest alternatives intelligently/rewrite it transparently when given as an argument). > 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 > It's worth noting that we *do* this for pypy, but we retain dev-python/pypy3. I'm not a huge fan of it there but I know why we have it -- so that one can test new versions of pypy in parallel even when they supply the same implementation/version of the Python language. > (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? thanks, sam
