observation: Sabayon being rolling and availability of older packages

[Sławomir Nizio]

There's an interesting property of distributions (especially relevant to
rolling release ones) that can be easily overlooked unless it's relevant
to somone's use case, and something that Sabayon does very well:
availability of older packages.

In Sabayon, older versions are kept for a certain time (something like
two weeks, but I'm not sure about that), not simply removed upon upload.

This way even if someone doesn't want or can't run "equo update" for
one, two weeks or maybe more should be still able to install packages
without the necessity to upgrade the whole system.

I'm not sure that I can tell it's "guaranteed" to work but it works in
practise.

It may be relevant to people with intermittent problems with adneternet,
I mean Internet, for example.

(Important detail here is that package files include both version and
revision in their name, and the revision - actually hash is different
when the package is rebuilt, so foo-1.2 from yesterday can be
differentated from foo-1.2 from today.)

I don't know if it's a standard thing in rolling release Linux
distributions. I can only tell about openSUSE Tumbleweed: there,
packages are kept for only a few days, but on the other hand snapshots
of the whole package sets are available, and kept for some longer time.

Oh, and Gentoo. Source tarballs are mirrored on Gentoo infrastructure,
not sure for how long but if a version expires, well it can still be
downloaded from project's site, and it seems that upstreams tend to keep
tarballs of older versions.

If someone has other examples, or thoughts on that, do tell!