Does JJ really prefer for me to think backwards? It wants me to start with the new and describe command, but with git I first make the changes and name the changeset at the end of the workflow.
I also often end up with in a dirty repo state with multiple changes belonging to separate features or abstractions. I usually just pick the changes I want to group into a commit and clean up the state.
Since it's git compatible, it feels like it must work to add files and keep files uncommitted, but just by reading this tutorial I'm unsure.
> Does JJ really prefer for me to think backwards? It wants me to start with the new and describe command, but with git I first make the changes and name the changeset at the end of the workflow.
A good way to think of it is that jj new is an empty git staging area. There's still a `jj commit` command that allows you to desc then jj new.
> I also often end up with in a dirty repo state with multiple changes belonging to separate features or abstractions. I usually just pick the changes I want to group into a commit and clean up the state.
jj split allows you do to this pretty well.
> Since it's git compatible, it feels like it must work to add files and keep files uncommitted, but just by reading this tutorial I'm unsure.
In jj you always have a commit - it's just sometimes empty, sometimes full, has a stable changeid regardless. jj treats the commit as a calculated value based on the contents of your folder etc, rather than the unit of change.
`jj new` simply means "create a new commit [ontop of <location>]" - you don't have to describe it immediately. I never do.
I know that the intention was to do that, and I tried forcing the habit, but I too found it counter-productive to invariably end up re-writing the description.
My preferred workflow is to start with a new change, pick the changes I want, then use jj commit to describe the change and create a new empty one on top. Feels very similar to my old git workflow.
If I end up with multiple features or abstractions in one change (equivalent to the “dirty repo”), jj split works very well as an alternative to the git add/git commit/repeat workflow tidying up one’s working copy.
I'm giving jj a try but one aspect of it I dislike is edits to files are automatically committed, so you need to defensively create empty new commits for your changes. As in, want to browse the repo from a commit 2 weeks ago? Well if you just checkout that commit and then edit a file, you've automatically changed that commit in your repo and rebased everything after it on top of your new changes. So instead you create a new branch off of the old commit and add an empty commit to that branch so any file changes don't end up rewriting the past 2 weeks of history. git is much nicer in that I can do whatever I want to the files and it won't change the repo until _I tell it to_.
Just don't ever use `edit`, use `new` instead; then your changes are tracked without making a mess. I think that's much nicer than juggling stashes in git.
As a git-ist (?), if I'd ever move away from git, it would be to avoid tooling that has idioms like this (like git too has), if `jj` just gonna surface a bunch of new "bad ideas" (together with what seems like really good ideas), kind of makes it feel like it isn't worth picking up unless you don't already know git.
jj edit is the biggest jj footgun I can think of, as other comments said just use jj new. But also if you do accidentally edit or change something jj undo works surprisingly well.
I found when using jj it worked best for me when I stopped thinking in commits (which jj treats as very cheap “snapshots” of your code) and instead focus on the “changes”. Felt weird for me at first, but I realized when I was rebasing with git that’s how I viewed the logical changes I made anyway, jj just makes it explicit.
jj auto-rebasing doesn’t matter until you push changes, and once you do it marks them immutable, preventing you from accidentally rebasing changes that have been shared.
`jj new` works like `git checkout` most by creating an empty revision on the top. `jj edit` on the other hand resembles `git checkout; [edits...]; git add -A; git commit --amend --no-edit`.
You would have had to run `jj edit` in order for this to happen, so I think it's a stretch to say you didn't ask for the edit?
This is the main difference though: in git files can be `staged`, `unstaged` or `committed`, so at any one time there are 3 entire snapshots of the repo "active".
In `jj` there is only one kind of snapshot (a change) and only one is "active" (the current working directory). When you make changes to the working directory you are modifying that "change".
As others have mentioned, the equivalent to `git checkout` would be `jj new`, which ensures a new empty change exists above the one you are checking out, so that any changes you make go into that new change rather than affecting the existing one.
The last paragraph might be the most important one:
> There's one other reason you should be interested in giving jj a try: it has a git compatible backend, and so you can use jj on your own, without requiring anyone else you're working with to convert too. This means that there's no real downside to giving it a shot; if it's not for you, you're not giving up all of the history you wrote with it, and can go right back to git with no issues.
But this is not true. They are interoperable but far from seamless. Those features mainly support migration use cases or things like git deployment from an repo managed in jj. Operations git does are not in jj’s log. You have to constantly import them. The project recommends a single primary interface.
Has anyone found a good code review workflow with `jj`? My problem is that GitHub doesn't remember the content of the last reviewed SHA, so every time I push a new change from jj, reviewers lose the delta from their last reviewed commit.
To work around this I stopped moving revs (squash/rebase) after review starts, which creates awkward local graphs if I have to merge from main for merge conflicts. Graphite works but it's $$$, and phabricator/reviewable/gerritt all have significant onboarding hurdles.
The last reviewed sha is generally available on the PR page (not the changes page) when you force push. There should be a changes since review link somewhere near the push.
When reviewing, you can also mark individual files as reviewed (useful in larger reviews where you're incrementally reviewing files). If you do this, only files that are changed will be expanded when you come back to the review.
yeah, this is where my complaint is - github shows a "compare" button when I force push, but it's not linked to the PR review. The "file changed" status is often not granular enough - if I change one line, force push, the entire file gets marked as unreviewed. the github "changes since your last review" is commit-based, not sha-based.
what I want is something like graphite/gerritt/google's critique where after each force push, the review page shows only the true delta between the two shas (similar to the "compare" button in github, bu as a reviewable unit).
poked around on github, doesn't look like the stacked PR feature has affected this "changes since your last review" selector yet :(
I would like more uniformity in the way jjui handles commands when you are viewing changes vs when you are viewing files within a single change.
Often I just make my changes and leave it there without `new`, as I am not sure which file should go in a single commit. I just leave it there and I interactively commit later.
For me to use `new` more, I would like the ability to also simply be able to get a tree view of all changes, which contains file which contains file changes, so I could can have marks that span multiple changes and then either `split` or `commit` or `squash` the change, idk if there is a good word for it. Right now I can only mark within a single change, and I lose it once I navigate up.
I use jj fairly regularly and I'm trying to understand what your approach means, but having difficulty following what you want to acheive here. Seems like you're using ambiguous language that isn't aligned - wdym by marks?
1) Are there any benefits in replacing a personal private project git repo with jj? I usually just commit straight to master in order to just not to lose the changes and be able to roll back.
2) Are there any pros in doing so in a project with many large binary files (3d models, images)?
You can switch an existing git repo to jj by using:
jj git init --git-repo my-repo
I think (but CANNOT PROMISE) that just removing the .jj folder will bring you back, but definitely take a backup of .git before you try this in case I’m wrong.
No that is correct when in colocate mode (which is the default mode). Simply removing the .jj folder will "de-jj" the repo entirely, but will leave you in a headless state. Simple to fix with a `git switch` though.
If you are _not_ in colocate mode, the .git folder is located _inside_ the .jj folder. So worth checking!
I tried jj for a few months. It was fun to learn a new thing, but I haven't had a single case of "wow, this would have been a pain with git". Then I went back to git (it's been 6 months now) and I haven't had a single case of "this is so painful, I wish something better existed".
So it felt like the XKCD on "standards": I now have one versioning system, if I learn jj I will have two. What for?
Don't get me wrong: it's nice that jj exists and some people seem to love it. But I don't see a need for myself. Just like people seem to love Meson, but the consequence for me is that instead of dealing with CMake and Autotools, I now have to deal with CMake, Autotools and Meson.
Is there a concise introduction / overview of jj? I've read 8 pages of this link and the author is still in preambles and considerations... Not my favourite style of article!
We all need to give ourselves a push and finally make the next step in version control. Github, Google, Microsoft, Meta (did I forget anyone relevant? Probably) should just join forces and finally make it happen, which should not be a problem with a new system that is backend compatible to Git. Sure, Github may lose some appeal to their brand name, but hey, this is actually for making the world a better place.
Every time I see a statement like this I wonder what specific features of git that people feel like are terrible enough that it’s time to completely start over. Besides “the UX is kinda shit and it’s confusing to learn”, which there are many solutions for already that don’t involve reinventing a pretty good wheel.
Coming from mercurial (which is older than git), git doesn't understand a branch. Instead of a branch you get a tag that moves, which is very different. Too often I'm trying to figure out where something came in, and but there is just a series of commits with no information of which commits are related. Git then developed the squash+rebase workflow which softof gets around this, but it makes commit longer (bad), and loses the real history of what happened.
Git was not the first DVCS, there were better ones even when it was made. But Linus pushed git and people followed like sheep.
(I'm using git, both because everyone else is, and also because github exists - turns out nobody even wants a DVCS, they want a central version control system with the warts of SVN fixed).
Git is basically fine even though the verbs are backwards - e.g. you shouldn't need to name branches, commits should be far more automatic, but the basic mechanisms are fine.
How we got git was cvs was totally terrible[1], so Linus refused to use it. Larry McEvoy persuaded Linus to use Bitkeeper for the Linux kernel development effort. After trying Bitkeeper for a while, Linus did the thing of writing v0 of git in a weekend in a response to what he saw as the shortcomings of Bitkeeper for his workflow.[2]
But the point is there had already been vcs that saw wide adoption, serious attempts to address shortcomings in those (perforce and bitkeeper in particular) and then git was created to address specific shortcomings in those systems.
It wasn't born out of just a general "I wish there was something easier than rebase" whine or a desire to create the next thing. I haven't seen anything that comes close to being compelling in that respect. jj comes into that bucket for me. It looks "fine". Like if I was forced to use it I wouldn't complain. It doesn't look materially better than git in any way whatsoever though, and articles like this which say "it has no index" make me respond with "Like ok whatever bro". It really makes no practical difference to me whether the VCS has an index.
[1] I speak as someone who maintained a CVS repo with nearly 700 active developers and >20mm lines of code. When someone made a mistake and you had to go in and edit the repo files in binary format it was genuinely terrifying.
[2] In a cave. From a box of scraps. You get the idea.
To be fair the "shortcomings" that spurred it on mainly were the Samba guys (or just one) reverse-engineering Bitkeeper causing the kernel free license getting pulled, which caused Linus to say "I can build my own with blackjack and pre-commit hooks" and then he did, addressing it toward his exact use case.
It gained tons of popularity mainly because of Linus being behind it; similar projects already existed when it was released.
When I tried both at that time hg was just really slow so I just adopted git for all my personal projects because it was fast and a lot better than cvs. I imagine others were the same.
It is not about starting over, like moving from CVS or Subversion to Git. jj is backend compatible to Git, so nothing really had to change on the backend.
It's just that although Git was created by Linus Torvalds it is not perfect and could be more beginner friendly. But efforts to improve this should be concerted, not individual efforts.
And it does not have to be jj. I just think there is room for improvement, and not to alienate old farts it could be called GitNext, GitStep, GitFlow or similar to emphasize that is still is just Git, only with an improved front end.
Maybe Linus Torvalds himself should start the initiative.
The cli and a few concepts have evolved with time past the model's knowledge cutoff dates, so you have to steer things a bit with skills and telling it to use --help a bit more regularly.
I find it reasonably good with lots of tweaking over time. (With any agent - ask it to do a retrospective on the tool use and find ways to avoid pain points when you hit problems and add that to your skill/local agents.md).
I expect git has a lot more historical information about how to fix random problems with source control errors. JJ is better at the actual tasks, but the models don't have as much in their training data.
I've gone all in on jj with a OSS framework I'm building. With just a little extra context, the agents have been amazingly adapt at slicing and dicing with jj. Gives them a place to play without stomping on normal git processes.
Let's be real, the only reason for these Rust software is to replace GPL tools with permissive license ones and push these cuck licenses a new normal. Big tech love this; they can take your work and give nothing back.
I also often end up with in a dirty repo state with multiple changes belonging to separate features or abstractions. I usually just pick the changes I want to group into a commit and clean up the state.
Since it's git compatible, it feels like it must work to add files and keep files uncommitted, but just by reading this tutorial I'm unsure.
A good way to think of it is that jj new is an empty git staging area. There's still a `jj commit` command that allows you to desc then jj new.
> I also often end up with in a dirty repo state with multiple changes belonging to separate features or abstractions. I usually just pick the changes I want to group into a commit and clean up the state.
jj split allows you do to this pretty well.
> Since it's git compatible, it feels like it must work to add files and keep files uncommitted, but just by reading this tutorial I'm unsure.
In jj you always have a commit - it's just sometimes empty, sometimes full, has a stable changeid regardless. jj treats the commit as a calculated value based on the contents of your folder etc, rather than the unit of change.
`jj new` simply means "create a new commit [ontop of <location>]" - you don't have to describe it immediately. I never do.
I know that the intention was to do that, and I tried forcing the habit, but I too found it counter-productive to invariably end up re-writing the description.
If I end up with multiple features or abstractions in one change (equivalent to the “dirty repo”), jj split works very well as an alternative to the git add/git commit/repeat workflow tidying up one’s working copy.
Like `jj commit -m 'Feature A' file1 file2` then `jj commit -m 'Feature B' file3 file 4`
As a git-ist (?), if I'd ever move away from git, it would be to avoid tooling that has idioms like this (like git too has), if `jj` just gonna surface a bunch of new "bad ideas" (together with what seems like really good ideas), kind of makes it feel like it isn't worth picking up unless you don't already know git.
i do this for example when i want to see a specific edit highlighted in my editor, it's a nice workflow i think
I found when using jj it worked best for me when I stopped thinking in commits (which jj treats as very cheap “snapshots” of your code) and instead focus on the “changes”. Felt weird for me at first, but I realized when I was rebasing with git that’s how I viewed the logical changes I made anyway, jj just makes it explicit.
jj auto-rebasing doesn’t matter until you push changes, and once you do it marks them immutable, preventing you from accidentally rebasing changes that have been shared.
This is the main difference though: in git files can be `staged`, `unstaged` or `committed`, so at any one time there are 3 entire snapshots of the repo "active".
In `jj` there is only one kind of snapshot (a change) and only one is "active" (the current working directory). When you make changes to the working directory you are modifying that "change".
As others have mentioned, the equivalent to `git checkout` would be `jj new`, which ensures a new empty change exists above the one you are checking out, so that any changes you make go into that new change rather than affecting the existing one.
> There's one other reason you should be interested in giving jj a try: it has a git compatible backend, and so you can use jj on your own, without requiring anyone else you're working with to convert too. This means that there's no real downside to giving it a shot; if it's not for you, you're not giving up all of the history you wrote with it, and can go right back to git with no issues.
To work around this I stopped moving revs (squash/rebase) after review starts, which creates awkward local graphs if I have to merge from main for merge conflicts. Graphite works but it's $$$, and phabricator/reviewable/gerritt all have significant onboarding hurdles.
When reviewing, you can also mark individual files as reviewed (useful in larger reviews where you're incrementally reviewing files). If you do this, only files that are changed will be expanded when you come back to the review.
what I want is something like graphite/gerritt/google's critique where after each force push, the review page shows only the true delta between the two shas (similar to the "compare" button in github, bu as a reviewable unit).
poked around on github, doesn't look like the stacked PR feature has affected this "changes since your last review" selector yet :(
I would like more uniformity in the way jjui handles commands when you are viewing changes vs when you are viewing files within a single change.
Often I just make my changes and leave it there without `new`, as I am not sure which file should go in a single commit. I just leave it there and I interactively commit later.
For me to use `new` more, I would like the ability to also simply be able to get a tree view of all changes, which contains file which contains file changes, so I could can have marks that span multiple changes and then either `split` or `commit` or `squash` the change, idk if there is a good word for it. Right now I can only mark within a single change, and I lose it once I navigate up.
jj git init --git-repo my-repo
I think (but CANNOT PROMISE) that just removing the .jj folder will bring you back, but definitely take a backup of .git before you try this in case I’m wrong.
If you are _not_ in colocate mode, the .git folder is located _inside_ the .jj folder. So worth checking!
So it felt like the XKCD on "standards": I now have one versioning system, if I learn jj I will have two. What for?
Don't get me wrong: it's nice that jj exists and some people seem to love it. But I don't see a need for myself. Just like people seem to love Meson, but the consequence for me is that instead of dealing with CMake and Autotools, I now have to deal with CMake, Autotools and Meson.
But nowadays I'm extremely lazy to attempt to learn this new thing. Git works, I kind of know it and I understand its flow.
Git was not the first DVCS, there were better ones even when it was made. But Linus pushed git and people followed like sheep.
(I'm using git, both because everyone else is, and also because github exists - turns out nobody even wants a DVCS, they want a central version control system with the warts of SVN fixed).
GitHub is an abomination.
How we got git was cvs was totally terrible[1], so Linus refused to use it. Larry McEvoy persuaded Linus to use Bitkeeper for the Linux kernel development effort. After trying Bitkeeper for a while, Linus did the thing of writing v0 of git in a weekend in a response to what he saw as the shortcomings of Bitkeeper for his workflow.[2]
But the point is there had already been vcs that saw wide adoption, serious attempts to address shortcomings in those (perforce and bitkeeper in particular) and then git was created to address specific shortcomings in those systems.
It wasn't born out of just a general "I wish there was something easier than rebase" whine or a desire to create the next thing. I haven't seen anything that comes close to being compelling in that respect. jj comes into that bucket for me. It looks "fine". Like if I was forced to use it I wouldn't complain. It doesn't look materially better than git in any way whatsoever though, and articles like this which say "it has no index" make me respond with "Like ok whatever bro". It really makes no practical difference to me whether the VCS has an index.
[1] I speak as someone who maintained a CVS repo with nearly 700 active developers and >20mm lines of code. When someone made a mistake and you had to go in and edit the repo files in binary format it was genuinely terrifying.
[2] In a cave. From a box of scraps. You get the idea.
It gained tons of popularity mainly because of Linus being behind it; similar projects already existed when it was released.
Too sad it didnt win the VCS wars.
If ur making an appeal on a forum like this u could have gone with ur favorite feature, or anything else really.
It's just that although Git was created by Linus Torvalds it is not perfect and could be more beginner friendly. But efforts to improve this should be concerted, not individual efforts.
And it does not have to be jj. I just think there is room for improvement, and not to alienate old farts it could be called GitNext, GitStep, GitFlow or similar to emphasize that is still is just Git, only with an improved front end.
Maybe Linus Torvalds himself should start the initiative.
I find it reasonably good with lots of tweaking over time. (With any agent - ask it to do a retrospective on the tool use and find ways to avoid pain points when you hit problems and add that to your skill/local agents.md).
I expect git has a lot more historical information about how to fix random problems with source control errors. JJ is better at the actual tasks, but the models don't have as much in their training data.
Most models don't have a 100% correct CLI usage and either hallucinate or use some deprecated patterns.
However `jj undo` and the jj architecture generally make it difficult for agents to screw something up in a way that cannot be recovered.