This repo is not a jj workspace. Run `jj git init --colocate

Error message

This repo is not a jj workspace. Run `jj git init --colocate` in {} and retry.

What it means

ensure_jj_repo_in walks up from the given path looking for a jj workspace root (via try_jj_root / jj_root_if_exists). If no jj workspace is found, it bails with this error telling the user to initialize one with `jj git init --colocate`. It guards all downstream jj operations that require an existing workspace.

Source

Thrown at src/vcs.rs:46

    }

    let git_dir = path.join(".git");
    if git_dir.exists() {
        let status = Command::new("jj")
            .current_dir(path)
            .args(["git", "init", "--colocate"])
            .stdout(std::process::Stdio::null())
            .stderr(std::process::Stdio::null())
            .status()
            .context("failed to run jj git init --colocate")?;
        if status.success() {
            if let Ok(root) = try_jj_root(path) {
                return Ok(root);
            }
        }
    }

    bail!(
        "This repo is not a jj workspace. Run `jj git init --colocate` in {} and retry.",
        path.display()
    );
}

pub fn jj_root_if_exists(path: &Path) -> Option<PathBuf> {
    let output = Command::new("jj")
        .current_dir(path)
        .arg("root")
        .output()
        .ok()?;
    if !output.status.success() {
        return None;
    }
    let root = String::from_utf8_lossy(&output.stdout).trim().to_string();
    if root.is_empty() {
        None
    } else {

View on GitHub (pinned to a747e741ae)

Solutions

Run `jj git init --colocate` in the directory named in the error message to create a colocated git+jj workspace, then retry.
cd into the correct project directory (one that is already a jj workspace) before running, or fix the configured path.
If it's an existing git repo you want to keep: `jj git init --colocate` in that repo converts it in place without losing history.
Verify `jj root` succeeds manually in the target directory to confirm the workspace is detected.

Example fix

// before
$ mytool sync
Error: This repo is not a jj workspace. Run `jj git init --colocate` in /home/me/project and retry.
// after
$ cd /home/me/project
$ jj git init --colocate
$ mytool sync

Defensive patterns

Strategy: validation

Validate before calling

use std::path::Path;
fn is_jj_workspace(dir: &Path) -> bool {
    dir.join(".jj").exists() || std::env::var("JJ_WORKSPACE").is_ok()
}
// before calling:
let dir = Path::new("/home/me/project");
if !is_jj_workspace(dir) {
    eprintln!("Run `jj git init --colocate` in {} first", dir.display());
    std::process::exit(1);
}

Prevention

Always run `jj git init --colocate` when converting an existing git repo before using jj-based tooling
Verify `jj root` succeeds in your project directory before running tools that depend on jj
Store absolute, existing workspace paths in tool configuration
Beware git worktrees and submodules — ensure the checkout you run from is itself jj-initialized

When it happens

Trigger: Calling ensure_jj_repo_in(path) (or ensure_jj_repo(), which passes the current directory) where neither the path nor any ancestor is a jj workspace — i.e. `jj root` fails at every level up the tree.

Common situations: Running the tool in a plain git repo that was never colocated with jj (no `jj git init --colocate` was run); running from a scratch/tmp directory; pointing the config at the wrong project path; jj workspace was deleted or the .jj directory was removed/gitignored; running inside a git worktree that jj does not recognize.

Related errors

AI-assisted analysis of nikivdev/code@a747e741ae (2026-09-01). Data as JSON: /api/errors/356fb25adebe4300. Report an issue: GitHub.