Interesting. I was not aware of the staging branch. I thought that patches are always merged into master and then automatically trickle down to unstable once all of the integration tests pass.
How often do you find yourself performing a rollback? I've always stuck to the stable channel, but I may give unstable a shot if it doesn't break too often, as you say.
That was how it worked in the past, but it becomes frustrating because some changes result in many, many package rebuilds which hold up everyone else, or otherwise drains resources of the CI system, which would be better spent building existing packages. Staging is generally where changes that result in mass rebuilds go (or may introduce large instability) in order to keep the main branch "up to date".
Changes that are backwards incompatible (but do not result in mass rebuilds) can and will often just go to master directly. For example, NixOS module changes rarely result in mass rebuilds, even if it breaks an API -- but changing the default kernel version does. The latter would go to staging.
I exclusively use the unstable branch on all my Nix/NixOS machines. I rarely do rollbacks. But it's important to note that I'm a developer with commit access, so I can basically "just" fix things if they're problematic. Not everyone has that luxury. (Many Linux distro maintainers likely operate this way, I guess. :)
There have been events in the past where unstable has had changes that made rollback impossible. In particular, if the bootloader becomes unstable somehow, your rollback capabilities are toast (and you won't know until you reboot, when it's too late). But I don't think anything like that has happened in a long time...
> I exclusively use the unstable branch on all my Nix/NixOS machines. I rarely do rollbacks. But it's important to note that I'm a developer with commit access, so I can basically "just" fix things if they're problematic. Not everyone has that luxury. (Many Linux distro maintainers likely operate this way, I guess. :)
An important thing with NixOS is that since the whole distro is built from a monorepo, it's also very easy for an advanced user to just git clone and fix the problematic things too (and hopefully send a pull request!).
How often do you find yourself performing a rollback? I've always stuck to the stable channel, but I may give unstable a shot if it doesn't break too often, as you say.