this post was submitted on 02 Aug 2025
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“Jujutsu (jj) is a version control system with a significantly simplified mental model and command-line interface compared to Git, without sacrificing expressibility or power (in fact, you could argue Jujutsu is more powerful). Stacked-diff workflows, seamless rebases, and ephemeral revisions are all natural with jj [...]”

Part 2 of the series is out and is here.

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[–] HaraldvonBlauzahn@feddit.org 2 points 18 hours ago* (last edited 17 hours ago) (1 children)

The mental model is fascinatingly simple. It is: You have a directed acyclical graph (DAG) of "changes", which are often drawn like this.. Then, you have a small set of commands that operate on that graph, e.g. adding changes, fusing two into one or splitting up one into two, adding nodes that have more than one parents, rebasing single nodes or a series of changes. And changing the content of these nodes in the commit graph is almost always done with the normal source code editor - everything one saves becomes already part of the graph when the next jj command is run.

Jujutsu does not use branches much because you are focused on the nodes in the commit graph. And instead of giving every of them manually a name, they are identified with change IDs. Branches are called "bookmarks", they can be attached to a commit graph node, and are used mostly for collaboration.

And when you push that graph of mutable changes to remote, they become a graph of normal commits that should not be changed under normal circumstances (because they are shared history now).

[–] atzanteol@sh.itjust.works 2 points 14 hours ago (5 children)

Jujutsu does not use branches much because you are focused on the nodes in the commit graph. And instead of giving every of them manually a name, they are identified with change IDs.

This is... unforgivably obnoxious. What's the point of this? That's like saying "Instead of giving every directory a name manually you identify them by inode." The entire point of branches is to have a name that has meaning to me that I can use to refer to work I'm doing.

As soon as you edit a file, the changes will be included in whatever revision you're currently editing—there's no separate staging area in Jujutsu.

I create log files of runs, temporary helper scripts, build output, etc. in my working copy all the time. And this thing is going to "save me the burden" of having to add files manually by just adding... everything it sees.

You'll have noticed that at no point so far did we ever think about creating a branch. That's because Jujutsu's relationship to branches is a bit different to Git's—they're just pointers that you move around so they point to whichever revision you want them to at a given time.

"Simpler" apparently means I get to do a lot more book-keeping than when I use git.

[–] HaraldvonBlauzahn@feddit.org 2 points 12 hours ago* (last edited 11 hours ago) (1 children)

But, did you try it? Myself, I was comfortable with working with it after one hour or two - after working with git for 18 or 19 years, and often being the first git user in my organization.

[–] atzanteol@sh.itjust.works 1 points 9 hours ago (1 children)

I've started to tinker with it. "auto commit everything" is an absolute deal-breaker for me. There's no world in which I want every file I create to be added to source control without asking. I create lots of log files and other temp files when I work. Maybe I just fetched some .json from a service and put it in tmp.json? Maybe I created a small shell script to automate something I'm doing? I guarantee I'm going to end up pushing that shit upstream by accident at some point.

[–] HaraldvonBlauzahn@feddit.org 1 points 8 hours ago

I create lots of log files and other temp files when I work. Maybe I just fetched some .json from a service and put it in tmp.json? Maybe I created a small shell script to automate something I'm doing?

You might be able to put them into .gitignore. But why not keep the shell script in a tools folder?

[–] naonintendois@programming.dev 2 points 13 hours ago (2 children)

Jj's closest equivalent of branches are bookmarks, but they don't auto update when you pull from a remote. I wish it was more like a git branch in that sense.

However, editing past commits and reorganizing the tree is MUCH easier in jj. It feels like the commands are more in line with what I want to do rather than having to figure out the specific set of git commands to do what I want.

I did find the "adding EVERYTHING" behavior to be annoying initially. My workaround was to create a local folder and add it to git ignore and push all those temp files there.

YMMV but I've found it much easier to manage complex workflows with jj compared to git.

[–] atzanteol@sh.itjust.works 1 points 9 hours ago* (last edited 9 hours ago) (2 children)

However, editing past commits and reorganizing the tree is MUCH easier in jj. It feels like the commands are more in line with what I want to do rather than having to figure out the specific set of git commands to do what I want.

I can see that - but that's a "less frequent" task than me switching between branches. And the auto-commit-everything mixed with "you need to lookup a hash ID for each thing you're working on" workflow is very frequent and obnoxious.

[–] naonintendois@programming.dev 1 points 1 hour ago

You don't always need the hash id. @ is equivalent to HEAD, there's also @- for HEAD~, @-- for HEAD~2, etc. with jj log the revset can also be a complex expression https://jj-vcs.github.io/jj/latest/revsets/. You can also create a bookmark to track a remote git branch that's also updated when you fetch. But you have to move the bookmark when you make changes locally.

[–] HaraldvonBlauzahn@feddit.org 0 points 8 hours ago* (last edited 8 hours ago)

I can see that - but that's a "less frequent" task than me switching between branches.

My observation is that one happens to edit the commit graph much more often because it is so effortless.

And the analogous thing to switching a branch is:

jj

to get the log. And then, with say "qx" being the abbreviated commit id I want to append the next change to:

jj new qx

and now I am already working at the right series of changes.

Because I like a lot to focus on one single thing, the next thing I do is often

 jj desc

which opens $EDITOR with the commit description and lets me write down what I am going to add or change.

That commit description also shows up in the log command, so I know always what the change is about.

[–] HaraldvonBlauzahn@feddit.org 1 points 12 hours ago* (last edited 11 hours ago) (3 children)

YMMV but I've found it much easier to manage complex workflows with jj compared

It is no secret that git's interface is a bit too complex - even XKCD has made fun of it.

But what is amusing is that people now have a kind of Stockholm Syndrome, and plain refuse to believe there could be something better.

(Perhaps motivated by the long list of half-assed helper interfaces and GUIs which just were hapless trying to hide the sprawling complexity).

[–] atzanteol@sh.itjust.works 1 points 9 hours ago (1 children)

But what is amusing is that people now have a kind of Stockholm Syndrome, and plain refuse to believe there could be something better.

Wow - way to just brush away any and all criticism as "that sounds like a you problem".

[–] HaraldvonBlauzahn@feddit.org 0 points 9 hours ago* (last edited 8 hours ago) (1 children)

jujutsu changes a lot of the affordances to manage changes and I understand that many people will be reluctant to use such a changed interface - for one, after they have spent so much time with learning the git CLI, and also because there are dozens of alternative git UIs and VCSes which claim to offer something simpler.

But: jujutsu offers about similar power and flexibility as git, while requiring much less UI complexity. The proof for this is the much, much smaller amount of required documentation as well as practice before one can work productively with it.

All the changed elements give a very orthogonal and cohesive whole, which is very rare for software of that complexity.

Will this work for everyone? Probably not, that happens extremely rarely.

Will many people pick it up on a whim? No, change does not happen that way. In the ideal case, a kind of logistic function but adoption will be very unlikely to be as rapid as git's adoption.

Will experienced git users drop the work they have to do and spend half a day to try a new tool? Some do, and this is good. Some don't, and this is also good.

So, no, I don't have a problem. People have time and decide to look at something or they don't. Both is fine.

[–] atzanteol@sh.itjust.works 1 points 3 hours ago

jujutsu changes a lot of the affordances to manage changes and I understand that many people will be reluctant to use such a changed interface

You lost all credibility when you just blamed my criticism on "stockholm syndrom". Sorry buddy.

[–] FizzyOrange@programming.dev 1 points 10 hours ago

It is no secret that git’s interface is a bit too complex

Right but that's mostly because the CLI is a mess, not because the fundamental data model is bad.

[–] naonintendois@programming.dev 1 points 10 hours ago (1 children)

Telling people they have Stockholm syndrome is not a good way to convince them to change their behavior. Present the pros, be honest about the cons and let people make their own decisions. The jj workflow isn't for everyone, and sometimes people's git workflows are simple enough that there isn't a benefit to learning a new tool. I like jj because I have to deal with complicated workflows for work and jj makes them much easier. At a different job it was much simpler and I wouldn't have paid too much attention to jj.

[–] atzanteol@sh.itjust.works 2 points 9 hours ago* (last edited 9 hours ago) (2 children)

I do a lot of complicated stuff with git - what sort of workflow does this solve for you?

git rebase -i and git squash work well for combining commits and cleaning up history. I'm not finding anything about jj yet that does better? And I'm finding a lot about it that are just deal breakers (auto-commit everything, make me lookup hashes of things).

[–] naonintendois@programming.dev 2 points 4 hours ago

I have to work with Gerrit, which requires amending existing commits after they've been pushed to the remote branch to address comments. I'll frequently have lots of commits I'm working on above the commit in review. Along with a couple other branches. Every commit also has to compile and pass tests. I'll frequently go git rebase -i --autosquash paired with git fixup. I've made mistakes before that are hard to untangle. With jj it's just jj edit .

Or if I want to insert a commit between two others it's just jj new -A to create a new commit after the change id (but BEFORE the previous change that was after the commit). With git I'd need to commit then rebase, put it in the right slot and recompile, rerun tests, re-edit. If I work on a branch I'd need to rebase, possible merge conflicts. jj just puts me on that commit then helps me manage merge conflicts going up. It's fewer commands focused on what I want to do and less on the tree like git.

[–] HaraldvonBlauzahn@feddit.org 0 points 8 hours ago* (last edited 8 hours ago)

squash exists but it squashes commits.

The rebase command is a bit more flexible but a key difference is handling of conflicts: They represent as regions with conflict markers in the conflicted text regions and all following commits/changes, and they disappear once the conflict has been resolved. No weird interim stated and git rebase --abort. If you want the old state back, you only need to do jj undo and that's it.

[–] HaraldvonBlauzahn@feddit.org 2 points 13 hours ago (1 children)

The entire point of branches is to have a name that has meaning to me that I can use to refer to work I'm doing.

You already have a name for every change/commit: The first line of the commit message, which you can write when you start work on it.

Branch names in git are temporary: When a branch is merged, its name disappaers.

[–] atzanteol@sh.itjust.works 1 points 9 hours ago

You already have a name for every change/commit: The first line of the commit message, which you can write when you start work on it.

No - that's a "description". You can't check that out. You need to jj log to get the hash of that to switch to it.

[–] BatmanAoD@programming.dev 1 points 13 hours ago* (last edited 13 hours ago)

For what it's worth, I agree with you about branches, and there are various ongoing discussions about how to make working with branches more convenient. I use an experimental feature called "advance branches" that makes it mostly fit my workflows, and the other benefits of jj are sufficient that I haven't switched back to git.

I create log files of runs, temporary helper scripts, build output, etc. in my working copy all the time.

The solution to this is to just have a more aggressive .gitignore. But also, note that the "working copy commit" isn't generally something you want to push or keep; think of it more like a combination of the git staging index and an automatic stash.

[–] HaraldvonBlauzahn@feddit.org 0 points 13 hours ago* (last edited 11 hours ago)

This is... unforgivably obnoxious.

Well, if you really don't like it after giving it consideration - use git. Nobody forces you to use jujutsu.