Add a shared tag for RC versions

[nbraud]

The CPython images provide rc and rc-slim tags to refer to whatever is the current development version, in addition to 3 / latest. Would it be possible to have those for PyPy?

[tianon]

It's certainly possible, but it's going to be pretty manual, and I'm not sure I get the benefit? I feel like the concept of "RCs" in Python is a little more well defined than in PyPy, where releases have previously gone from "beta" to "GA" without much warning (because by the time they're released as a beta, they're already pretty stable 😄).

[nbraud]

Hi Tianon!

It's certainly possible, but it's going to be pretty manual, and I'm not sure I get the benefit?

My usecase is simply being able to pull the latest development version in CI for downstream projects, and be informed automatically if some change breaks our testsuite. It's pretty helpful in making sure we stay compatible with newer versions of CPython or PyPy without having to scramble right after a new release.

I feel like the concept of "RCs" in Python is a little more well defined than in PyPy, where releases have previously gone from "beta" to "GA" without much warning (because by the time they're released as a beta, they're already pretty stable smile).

I'm not sure I follow, here. There are already various tags (such as 3.8) to select development versions (that are newer than latest), all I'm asking about is a tag that allows selecting the development version (without knowing that it is currently 3.8)

If the concept of an RC version doesn't work for PyPy's development cycle, calling the tag dev or somesuch is fine; I only mentioned rc since it is the equivalent in CPython's images.

[tianon]

I guess what I'm trying to get at is that https://www.pypy.org/download.html (or even https://www.pypy.org/download_advanced.html) doesn't really differentiate between 3.8, 3.7, or 2.7, even though that 3.8 is considered a "beta" release.

The only place that I'm aware of that really makes it clear that 3.8 is "beta" is the blog post which announced it: https://www.pypy.org/posts/2021/10/pypy-v736-release.html (and my understanding previously has been that it stays beta until it isn't anymore, and that the "beta" status of it thus isn't particularly well-defined, which makes it a bit difficult to track accurately).