May 2nd, 2011 by lucas
Here is my attempt at a summary of the rolling discussion currently happening on debian-devel@. It might not be complete, it’s probably a bit biased, but I hope that it’s still better than nothing. It was also posted on debian-devel@.
If you are involved in Debian development, please discuss it on debian-devel@, rather than in the comments of this blog.
If you want to provide feedback about the Debian rolling idea, use this Doodle poll and/or the comments of this blog.
Update : Someone had the good idea to vandalize the poll, and remove all the votes from people in favor of rolling. Before the vadalism (log), the results were:
37 votes: I am a Debian user, I use testing or unstable, and I would like rolling to happen.
6 votes: I am a Debian user, I use testing or unstable, and I DON’T want rolling to happen.
17 votes: I am a Debian user, I use stable, and I would like rolling to happen.
3 votes: I am a Debian user, I use stable, and I DON’T want rolling to happen.
7 votes: I am NOT a Debian user, but I would probably use it if rolling happened.
1 vote: I am NOT a Debian user, and I don’t care about rolling.
There’s some user demand for rolling releases. For evidence, one can look at the usage of Debian testing or unstable which clearly goes further than the Debian development community. Or at the quickly growing market share of ArchLinux. Or at the interest in LinuxMint and Aptosid. Or at the DPL’s report of his interactions with the press.
Debian’s only official product is its stable releases. While it’s a clearly great and useful product, many users and developers don’t recognize themselves in it: it contains software that is too old for their needs. The success of Ubuntu is related to this problem: Ubuntu proposes a different compromise between stability and up-to-date-ness.
While concurrencing Ubuntu with more frequent stable releases (released every 6-months, for example) doesn’t look like the right thing to do, Debian is in a perfect position to provide a rolling release with marginal additional work, since Debian already has testing (and unstable) to build on.
The rolling discussion investigates how we could endorse the concept of a rolling release, provided as a product in addition to stable releases. This rolling release would be based on the current testing branch.
Benefits for Debian:
- Attract users who think that testing is only a development branch, and want newer software than what one finds in stable. Those users are likely to be rather advanced users (free software developers and contributors), thus interesting to work with (able to submit good-quality bug reports, etc). Some of them could also become Debian contributors. And even if they don’t, more users of testing/rolling means more testers of the next stable release [remember how the bug reporting rate of Ubuntu is higher than Debian's -- some areas of Debian could use more testers].
- Give back to the free software world by providing a platform where new upstream releases would quickly be available to users. Since users would be able to test new upstream releases earlier, they would be able to provide feedback to upstream devs earlier, contributing to a shorter feedback loop. Debian is often identified by upstream developers as the platform with releases from two years ago. I would love to see Debian in a position to contribute more to improviing the quality of the Free Software world.
- Get back some attention that is currently taken away from Debian by derivatives. This is important to carry our political or technical messages, which are not necessarily carried out by our derivatives.
Current proposed plan for rolling
(Disclaimer: this is mostly my view. It is shared by others, but some details might not be)
rolling is mostly about (external) communication. It is not expected to change our development processes fundamentally.
It would be a statement by the project (through a GR, for example). A very preliminary draft was proposed by Raphael Hertzog:
Title: Debian endorses usage of testing by end-users, and renames it to rolling
The Debian project recognizes that the Debian testing distribution—initially created to make it easier to prepare and test the next stable release—has become a useful product of its own. It satisfies the needs of users who are looking for the latest stable versions of software and who can cope (or even appreciate) a system that’s constantly evolving.
The Debian project decides to endorse this usage and will strive to provide a good experience to users of “testing”. To better communicate this policy change to our users, “testing” will be renamed “rolling”.
Yes, it’s mostly “PR bullshit”, and I don’t expect it to significantly change Debian development processes. However, communication is necessary if we want to attract new users. What would change is more attention from developers to what happens in testing/rolling, which is a good thing since a better testing/rolling makes it easier to create stable releases from it.
Most of the discussion is about the influence of the introduction of ‘rolling’ on Debian development processes, and in particular, on the painful process resulting in stable releases. Many fear that, with ‘rolling’, it will be harder to get stable releases out.
The root question is: if we do rolling, what do we do during freezes? Several options have been mentioned in the thread:
- We could decide not to do anything special: just freeze rolling for ~6 months, as we used to freeze testing. That might bore people who like the constant flux of new upstream releases, but if we decide that it’s the only way to ensure high-quality stable releases, so be it.
- We could decide to fork a frozen branch when we freeze, and continue to manage rolling using migrations from unstable.
- We could mix both solutions: freeze rolling for 3 months, so that most of the stabilization work occurs with a single active branch, and then, for the final release preparation, fork frozen off rolling, and unfreeze rolling.
Two kinds of objections have been raised:
- Those against the rolling concept:
- “It’s only about PR, Debian isn’t about PR.” Answer: PR does matter sometimes, especially if we want to attract users.
- “There’s usually no installer for it, other than installing the latest stable release and dist-upgrading, which doesn’t always work.” Answer: True; but it sounds like an acceptable problem. And if upgrades from the latest stable fail, it’s an RC bug, so we would like to know. And if we do get d-i betas, it’s a great way to get user testing for them.
- It will split the developers base between supporting ‘rolling’ and supporting stable releases (which also need to be supported after they have been released). Answer: already the case today.
- Testing is not targeted at end users, but is a tool for the release team to create stable releases. It needs to stay that way. Answer: really, can’t we do both?
- Renaming testing to rolling will require changes in many parts of Debian infrastructure. Answer: some problems can be mitigated by keeping a testing symlink. The remaining impact needs to be evaluated.
- Those against the two development branches during freezes problem:
- It splits the users and developers base between two branches (less users means less bug reports ; less developers means less bug fixing). Answer: true.
- It requires the use of two different entry points for packages (unstable for packages targeted at rolling, frozen-proposed-updates for packages targeted at frozen). Answer: true.
- All in all, huge overhead for the release team. Answer: true.
- Overhead for developers, who need to support two targets. Answer: true.
- Just after a stable release, we would start the next release from rolling, instead of stable. So we would start from a “less clean” base. Answer: true.
- It’s even worse if you consider staged freezes (freezing base packages earlier than the rest of the distribution, for example). Answer: true; but is it really a problem if some base packages are frozen in rolling for a few months?
Other things that were discussed:
- possible changes to processes around testing to make it more usable (reduce the set of architectures required for migration to testing ; allow/encourage usage of t-p-u to rebuild unstable packages that are ready to transition except for the fact that they are entangled in a transition ; have different level of RC bugs: there are RC bugs that are acceptable in rolling that are not acceptable in stable)
- PPAs for Debian
- Developer activity during freeze (developer temporarily stopping to work on Debian during freezes)
- Let’s improve our packaging process or reduce the duration of our freezes before introducing rolling. Answer: but then, shouldn’t we also stop doing stable releases for a while? ;)
- Setting up an official “rolling instance”. Answer: that can’t work. detailed answer
- Using unstable instead of testing as the basis for rolling. Answer: there seems to be more demand for something similar to testing, than for something similar to unstable.
Tentative personal conclusion
I have the impression that advertising testing as a rolling release usable by end-users is generally considered a good thing.
The renaming of testing to rolling is not as consensual, but most opponents have a “whatever ; if you want” position.
How we deal with freezes is the hard point in this discussion. I’m personnally in favor of the “freeze rolling for 3 months, then fork frozen and unfreeze rolling” plan, though it has some problems too (it is not clear whether the required manpower really decreases at the end of freezes).
Where do we go from there? After another round of discussion, we might postpone the “how to deal with freezes” question to later, and proceed with a GR to measure the support for the “testing for end-users + s/testing/rolling/” proposal.