On Thu, Mar 12, 2020 at 12:29:45PM -0700, Elijah Newren wrote: > First, note that this particular breakage would have occurred > regardless of the default setting, because the problem was that they > setting rebase.backend to an unrecognized value, not that we used a > different backend than they were used to. If I understand correctly, it was also a setting that never worked in any released version of Git. It was magic that was only ever in 'next'. As annoying as it is to experience breakage, I'm not _too_ sympathetic to this case, because that is part of the cost of running the bleeding edge of 'next' or even 'master'. I.e., I think we have to make a cutoff _somewhere_ to say "this is something that made it to the general public, and therefore we can't break backwards compatibility" to keep our sanity during development. And it seems like tagged releases are a pretty good cutoff to me. Though in this particular case, I don't mind too much just leaving "am" as an alias for "apply" (it was actually the first thing I tried when writing my earlier emails, but I'm probably not a representative user there). Putting that in a release, though, may mean supporting it forever. :) > - We had multiple complaints this cycle about rebase.backend=apply > merging things incorrectly with the only workaround being to use the > merge backend[3,4] > - The rebase-backend topic wasn't merged down to master until less > than a week before -rc0. (For a variety of reasons.) A big change > like this probably would have been better to merge down earlier in > some cycle. It did feel a bit quick to me, hitting near the end of the cycle. We've had the apply backend as the default for a decade, so even if there are problems with it, they're known issues. So I don't think there's a particular hurry. I'm not entirely convinced that cooking it longer during the next cycle will turn up a lot of new data (I did find a few issues, but the real test is the long-tail of weird use cases that we won't see until an actual release). But it probably doesn't hurt much to take it slow; it just delays a few bug-fixes (which people can still get by setting a config option). I guess like your email I'm going back and forth between the two options. I think that means it probably doesn't matter _too_ much either way. -Peff
