Jujutsu: Keeping a file untracked

Coming from Git, I am used to a workflow where I can create a file in my repository (maybe a temporary script, or a local configuration file) and just never git add it. It sits there, listed as untracked in git status, invisible to my commits but available for my use. I never needed to add it to .gitignore since I simply never staged it.

When I started using Jujutsu, I ran into a small friction point with this habit. Jujutsu is designed to be more automatic than Git. By default, it automatically tracks all files in your working copy that aren't ignored by .gitignore. This means as soon as I create that temporary file, it will be included in the next snapshot, and jj status shows it as added.

This behavior is controlled by the snapshot.auto-track configuration setting. You can customize this setting using file patterns to exclude specific files. For example, to keep a file named foo.txt untracked, you can run:

jj config set --repo snapshot.auto-track "all() & ~foo.txt"
# Run the following if the file has already been snapshotted
jj file untrack foo.txt

You can still manually track it later if needed using jj file track foo.txt.

To untrack additional files later, you can append a new pattern to the existing configuration:

jj config set --repo snapshot.auto-track "$(jj config get snapshot.auto-track) & ~bar.txt"

If this is too much to type every time, you can define a Jujutsu alias in ~/.config/jj/config.toml:

[aliases]
ignore = [
  'util', 'exec', '--', 'bash', '-c',
  'jj config set --repo snapshot.auto-track "$(jj config get snapshot.auto-track) & ~$0" && jj file untrack $0'
]

Then, simply run:

jj ignore foo.txt
jj ignore bar.txt

I've been using this approach with my jj aliases for a while, and it works great!