It seems like a very contrived example to me. We have been running rebase/fast-forward only for close to 10 years now, and I have never experienced anything that unfortunate.
I run in to this quite frequently, even on projects where I'm the only one working on it (I tend to have a lot of things going on in parallel). Once branches diverge and commits accumulate it can become a right pain. Usually my solution is to merge master into the branch just to keep up to date and then just undo everything, make one new commit in the master, and rebase that. But in some more difficult cases it was "just merge and fuck it because life's too short". I've also just manually "copy/paste merged" things to a new branch, because that seemed quicker than dealing with all the merges/conflicts.
Maybe there are better ways of doing this, and arguably I shouldn't have all these long-lived branches in the first place (but it works well for me, so...), but it's not that much of a contrived edge case.
This is the problem here. If you have multiple long-lived branches, there's no technical solution to preventing rot -- you must actively keep them in sync.
Regularly merging in main is the opposite of the proper solution. Constantly rebasing on top of main is the proper solution.
> If you have multiple long-lived branches, there's no technical
> solution to preventing rot -- you must actively keep them in sync.
> Regularly merging in main is the opposite of the proper solution.
> Constantly rebasing on top of main is the proper solution.
Well, merge actually works much smoother and rebase gives a lot more grief, so the problem is with rebase.
> Regularly merging in main is the opposite of the proper solution. Constantly rebasing on top of main is the proper solution.
The "proper" solution is the one that allows me to get stuff done. The only thing that matters is how the main branch ends up looking in the end, and what I do before that isn't really all that important.
Another problem with rebase is when multiple people are working on the branch; it requires careful coordination if you don't want to lose work. Overall, just merge in main is usually the best strategy here.
Given that this scenario is common for you but sounds contrived to others, I would argue that this doesn't work well for you. It's just familiar enough that you're willing to deal with some pain.
Short-lived feature branches sidestep this hell. Longer-lived projects can almost always be partitioned into a series of shorter mergeable steps. You may need support/buy-in from your manager, I hope you get it.
I know some people think this is crazy, but it works well for me and I'm fairly productive like this, usually producing fairly good code (although I'm not an unbiased source for that claim).
In the end I don't want to radically change my workflow to git or other tooling; I want the tooling to adjust to the workflow that works well for me.
So probably? But I want to avoid https://i.redd.it/jdqjhi8qv3x71.jpg
If every error in your system needs a separate entry in the error enum, or every change needs an entry in the changelog - loads of changes will try to modify the last line of the file.
If order actually matters then yeah, git can't magically know where each new line should go.
I'm not saying these situations are impossible. But you can work towards reducing when they arise. If everyone needs to change the same file, then it sounds like something should be refactored (it's probably a quite big file as well?).
If every error needs to go to the same error enum, that sounds like an error enum that might benefit from being split up.
And if every change needs to write to a common changelog file, I would personally find a new way to produce that changelog.
If it's that big a painpoint, then I would look into different ways to get around it.
Rebase is still by far the most common case in our repo, as yes, these cases appear very rarely. But when they do happen, it's often worth it to do a merge and mess up a history a little bit (or squash, which messes with history in another way) rather than resolving conflicts over and over.
Someone else was also suggesting rerere for this use case, but I've never used it myself and I don't know how well it actually handles these types of use cases.
But we try to reduce the chance this happens quite a bit, by avoiding letting files grow too big, for example.
Other things we do, is use codeformatting with rules that reduce the chance of merge conflicts. For instance, instead of having imports like:
import SomePackage.{A, B, C}
import SomePackage.A
import SomePackage.B
import SomePackage.C
Sadly, my current approach is to just reset my development branch to the merge base and make one huge commit, and then rebase.
When that happens, we look into if it's possible to do more frequent merges (fast-forward rebases through Gerrit, to be specific) of our smaller commits to master, so we don't accumulate too much in isolation.
I find it helps reducing bugs as well, if two or more members are doing active work in the same area in that way, it's not good to be working in complete isolation as it just opens up for bugs because of incompatibility with the work going on in parallel.