jj/docs/FAQ.md
Stephen Jennings 1c672d7563 docs: Add FAQ for keeping changes to tracked files
The question "How do I avoid committing changes to files?" comes up a lot in
chat, and the solution is not obvious. It will be useful to have a description
with an example we can link to.

The wording of the similar question "How can I keep my scratch files in the
repository?" was tweaked to emphasize the difference between keeping untracked
files in the workspace and keeping changes tracked files out of published
history.
2024-09-03 17:23:58 -07:00

12 KiB

Frequently asked questions

Why does my branch not move to the new commit after jj new/commit?

If you're familiar with Git, you might expect the current branch to move forward when you commit. However, Jujutsu does not have a concept of a "current branch".

To move branches, use jj branch set.

I made a commit and jj git push --all says "Nothing changed" instead of pushing it. What do I do?

jj git push --all pushes all branches, not all revisions. You have two options:

  • Using jj git push --change will automatically create a branch and push it.
  • Using jj branch commands to create or move a branch to either the commit you want to push or a descendant on it. Unlike Git, Jujutsu doesn't do this automatically (see previous question).

Where is my commit, why is it not visible in jj log?

Is your commit visible with jj log -r 'all()'?

If yes, you should be aware that jj log only shows the revisions matching revsets.log by default. You can change it as described in config to show more revisions.

If not, the revision may have been abandoned (e.g. because you used jj abandon, or because it's an obsolete version that's been rewritten with jj rebase, jj describe, etc). In that case, jj log -r commit_id should show the revision as "hidden". jj new commit_id should make the revision visible again.

See revsets and templates for further guidance.

How can I get jj log to show me what git log would show me?

Use jj log -r ... The .. operator lists all visible commits in the repo, excluding the root (which is never interesting and is shared by all repos).

jj is said to record the working copy after jj log and every other command. Where can I see these automatic "saves"?

Indeed, every jj command updates the current "working-copy" revision, marked with @ in jj log. You can notice this by how the commit ID of the working copy revision changes when it's updated. Note that, unless you move to another revision (with jj new or jj edit, for example), the change ID will not change.

If you expected to see a historical view of your working copy changes in the parent-child relationships between commits you can see in jj log, this is simply not what they mean. What you can see in jj log is that after the working copy commit gets amended (after any edit), the commit ID changes.

You can see the actual history of working copy changes using jj obslog. This will show the history of the commits that were previously the "working-copy commit", since the last time the change id of the working copy commit changed. The obsolete changes will be marked as "hidden". They are still accessible with any jj command (jj diff, for example), but you will need to use the commit id to refer to hidden commits.

You can also use jj obslog -r on revisions that were previously the working-copy revisions (or on any other revisions). Use jj obslog -p as an easy way to see the evolution of the commit's contents.

Can I prevent Jujutsu from recording my unfinished work? I'm not ready to commit it.

Jujutsu automatically records new files in the current working-copy commit and doesn't provide a way to prevent that.

However, you can easily record intermediate drafts of your work. If you think you might want to go back to the current state of the working-copy commit, simply use jj new. There's no need for the commit to be "finished" or even have a description.

Then future edits will go into a new working-copy commit on top of the now former working-copy commit. Whenever you are happy with another set of edits, use jj squash to amend the previous commit.

If you have changes you never want to put in a public commit, see: How can I keep my scratch files in the repository without committing them?

For more options see the next question.

Can I interactively create a new commit from only some of the changes in the working copy, like git add -p && git commit or hg commit -i?

Since the changes are already in the working-copy commit, the equivalent to git add -p && git commit/git commit -p/hg commit -i is to split the working-copy commit with jj split -i (or the practically identical jj commit -i).

For the equivalent of git commit --amend -p/hg amend -i, use jj squash -i.

Is there something like git rebase --interactive or hg histedit?

Not yet, you can check this issue for updates.

To reorder commits, it is for now recommended to rebase commits individually, which may require multiple invocations of jj rebase -r or jj rebase -s.

To squash or split commits, use jj squash and jj split.

How can I keep my scratch files in the repository without committing them?

You can keep your notes and other scratch files in the repository, if you add a wildcard pattern to either the repo's gitignore or your global gitignore. Something like *.scratch or *.scratchpad should do, after that rename the files you want to keep around to match the pattern.

If you keep your scratch files in their own directory with no tracked files, you can create a .gitignore file in that directory containing only *. This will ignore everything in the directory including the .gitignore file itself.

If $EDITOR integration is important, something like scratchpad.* may be more helpful, as you can keep the filename extension intact (it matches scratchpad.md, scratchpad.rs and more). Another option is to add a directory to the global .gitignore which then stores all your temporary files and notes. For example, you could add scratch/ to ~/.git/ignore and then store arbitrary files in <your-git-repo>/scratch/.

You can find more details on gitignore files here.

How can I avoid committing my local-only changes to tracked files?

Suppose your repository tracks a file like secret_config.json, and you make some changes to that file to work locally. Since Jujutsu automatically commits the working copy, there's no way to prevent Jujutsu from committing changes to the file. But, you never want to push those changes to the remote repository.

One solution is to keep these changes in a separate commit branched from the trunk. To use those changes in your working copy, merge the private commit into your branch.

Suppose you have a commit "Add new feature":

$ jj log
@  xxxxxxxx me@example.com 2024-08-21 11:13:21 ef612875
│  Add new feature
◉  yyyyyyyy me@example.com 2024-08-21 11:13:09 main b624cf12
│  Existing work
~

First, create a new commit branched from main and add your private changes:

$ jj new main -m "private: my credentials"
Working copy now at: wwwwwwww 861de9eb (empty) private: my credentials
Parent commit      : yyyyyyyy b624cf12 main | Existing work
Added 0 files, modified 1 files, removed 0 files

$ echo '{ "password": "p@ssw0rd1" }' > secret_config.json

Now create a merge commit with the branch you're working on and the private commit:

$ jj new xxxxxxxx wwwwwwww
Working copy now at: vvvvvvvv ac4d9fbe (empty) (no description set)
Parent commit      : xxxxxxxx ef612875 Add new feature
Parent commit      : wwwwwwww 2106921e private: my credentials
Added 0 files, modified 1 files, removed 0 files

$ jj log
@    vvvvvvvv me@example.com 2024-08-22 08:57:40 ac4d9fbe
├─╮  (empty) (no description set)
│ ◉  wwwwwwww me@example.com 2024-08-22 08:57:40 2106921e
│ │  private: my credentials
◉ │  xxxxxxxx me@example.com 2024-08-21 11:13:21 ef612875
├─╯  Add new feature
◉  yyyyyyyy me@example.com 2024-08-21 11:13:09 main b624cf12
│  Existing work
~

Now you're ready to work:

  • Your work in progress xxxxxxxx is the first parent of the merge commit.
  • The private commit wwwwwwww is the second parent of the merge commit.
  • The working copy (vvvvvvvv) contains changes from both.

As you work, squash your changes using jj squash --into xxxxxxxx. Or, you can keep your changes in a separate commit and remove ttsqqnrx as a parent:

# Remove the private commit as a parent
$ jj rebase -r vvvvvvvv -d xxxxxxxx

# Create a new merge commit to work in
$ jj new vvvvvvvv wwwwwwww

To avoid pushing change wwwwwwww by mistake, use the configuration git.private-commits:

$ jj config set --user git.private-commits 'description(glob:"private:*")'

I accidentally changed files in the wrong commit, how do I move the recent changes into another commit?

Use jj obslog -p to see how your working-copy commit has evolved. Find the commit you want to restore the contents to. Let's say the current commit (with the changes intended for a new commit) are in commit X and the state you wanted is in commit Y. Note the commit id (normally in blue at the end of the line in the log output) of each of them. Now use jj new to create a new working-copy commit, then run jj restore --from Y --to @- to restore the parent commit to the old state, and jj restore --from X to restore the new working-copy commit to the new state.

How do I resume working on an existing change?

There are two ways to resume working on an earlier change: jj new then jj squash, and jj edit. The first is generally recommended, but jj edit can be useful. When you use jj edit, the revision is directly amended with your new changes, making it difficult to tell what exactly you change. You should avoid using jj edit when the revision has a conflict, as you may accidentally break the plain-text annotations on your state without realising.

To start, use jj new <rev> to create a change based on that earlier revision. Make your edits, then use jj squash to update the earlier revision with those edits. For when you would use git stashing, use jj edit <rev> for expected behaviour. Other workflows may prefer jj edit as well.

How do I deal with divergent changes ('??' after the change ID)?

A divergent change represents a change that has two or more visible commits associated with it. To refer to such commits, you must use their commit ID. Most commonly, the way to resolve this is to abandon the unneeded commits (using jj abandon <commit ID>). If you would like to keep both commits with this change ID, you can jj duplicate one of them before abandoning it.

How do I deal with conflicted branches ('??' after branch name)?

A conflicted branch is a branch that refers to multiple different commits because jj couldn't fully resolve its desired position. Resolving conflicted branches is usually done by setting the branch to the correct commit using jj branch set <commit ID>.

Usually, the different commits associated with the conflicted branch should all appear in the log, but if they don't you can use jj branch listto show all the commits associated with it.

How do I integrate Jujutsu with Gerrit?

At the moment you'll need a script, which adds the required fields for Gerrit like the Change-Id footer. Then jj can invoke it via an $EDITOR override in an aliased command. Here's an example from an contributor (look for the jj signoff alias).

After you have attached the Change-Id: footer to the commit series, you'll have to manually invoke git push of HEAD on the underlying git repository into the remote Gerrit branch refs/for/$BRANCH, where $BRANCH is the base branch you want your changes to go to (e.g., git push origin HEAD:refs/for/main). Using a co-located repo will make the underlying git repo directly accessible from the working directory.

We hope to integrate with Gerrit natively in the future.