On Wed, Sep 18, 2024 at 04:28:21PM -0700, Junio C Hamano wrote: > Removal of support for core.preferSymlinkRefs at Git 3.0 boundary, > so that we only write textual symrefs for things like HEAD and > refs/remotes/origin/HEAD, and still understand symbolic links used > as symrefs in existing repositories, is a serious proposal this > patch series makes. I probably don't have have to say that I fully support dropping support for the writing side of this :) I was also recently reminded that we still have ".git/branches", which I'd very much like to drop support for with Git 3.0, too. I'll send a separate patch series for that soonish. > But at the same time, this is an RFC. I wrote it to serve as a > candidate for BCP, a guide to those who want to add an entry to the > breaking changes document. I think anything that is described in > the breaking changes document has to become a patch series that > spans multi-year effort, and that must be done with care. > > - The proposal phase. A breaking change is outlined, transition > plan is given, and the first step of the transition (often, > starting to give a warning and offering an alternative to the > feature planned to be removed are involved) is presented. The > aim is that after N years, the user base will be aware of the > upcoming removal and would already be prepared to be able to work > with Git 3.0 that lacks the removed feature. > > In this series, [Patch 1/4] does this. > > - The Git 3.0 phase. A breaking change is actually implemented. > It optionally can offer help to those who procrastinated until > the last-minute to break them, but the feature itself is gone. > > In this series, [PATCH 2/4] and [Patch 3/4] do this. > > - Clean-up phase. If the previous phase added an additional > transition help, after M years, such a help meant for transition > would be removed. > > In this series, [PATCH 4/4] does this. > > What I want people to think about is how to ensure quality of the > Git 3.0 phase. We can iterate and polish the proposal phase with as > much time as we want to spend, just like any new feature. But Git > 3.0 phase is with a solid deadline, and before that time, we cannot > remove the feature for real. Would we cook such steps in 'next' > forever until the actual Git 3.0? To those users who are running > 'next' based Git, it would mean that some of the changes the > breaking changes document listed would come a lot earlier to them. > On the other hand, unless we somehow have a way to expose willing > volunteers an early access to these "big changes", there is no way > for them to be as stable and tested. We should not plan to scramble > and be able to perfect these changes between Git v3.0-rc0 and Git > v3.0 final. > > Or perhaps use the "experimental.*" configuration stored in the > user's ~/.gitconfig to let users opt into Git 3.0 features (one of > which may be that textual symrefs are always used regardless of the > core.preferSymlinkRefs setting)? That way, we can merge these big > changes early without worrying about accidentally affecting the > end-user population. I guess you've split this out into a separate discussion by now at [1], right? I've already commented on that series, so I'm not going to repeat what I've said here :) Patrick [1]: <xmqq7cb77810.fsf@gitster.g>
