jdx/mise · error

watch_files command failed

Error message

watch_files command failed: {status}

What it means

This error is thrown in the watch_files command executor when a spawned subprocess (the file-watching command) exits with a non-zero status. The command is run with a cleared environment plus explicitly passed env vars and stdout redirected to stderr. It signals that the watcher process itself failed, not that mise failed to spawn it.

Solutions

  1. Run the watch command manually with the same arguments to see its actual error output (stdout/stderr is forwarded to stderr)
  2. Fix the arguments or configuration of the underlying watch command so it exits 0
  3. Check that the env vars being forwarded are correct and that env_clear is not dropping vars the watcher needs
  4. Verify the target tool/binary the watcher invokes is installed and on PATH

Example fix

// before
mise watch --bad-flag src
// after
mise watch --correct-flag src
Defensive patterns

Strategy: try-catch

Validate before calling

// verify the watch command exits cleanly before relying on it
mise watch --dry-run src || echo "watch command itself fails"

Try / catch

match result {
    Err(e) if e.to_string().contains("watch_files command failed") => {
        eprintln!("watcher exited non-zero; rerun the command manually to see its error");
    }
    Err(e) => return Err(e),
    Ok(v) => v,
}

Prevention

When it happens

Trigger: The child process spawned in `execute` returns a failing exit status from `c.status()`; any invocation of the watch_files inline command whose underlying watcher binary or script exits non-zero.

Common situations: The watch command crashes on invalid arguments, the watched tool binary is missing or misconfigured, environment variables passed to the watcher are wrong, or the watcher is killed and reports a non-zero code.

Understand the failure class

Background: "git command failed": what it means when a tool shells out to git and git exits non-zero — this error's family across 21 libraries.

Related errors

AI-assisted analysis of jdx/mise@533346cc37 (2026-09-17). Data as JSON: /api/errors/6c4a8724390c04a1. Report an issue: GitHub.

Appendix: source

Thrown at src/watch_files.rs:128

        "MISE_PROJECT_ROOT".to_string(),
        root.to_string_lossy().to_string(),
    );
    // TODO: this should be different but I don't have easy access to it
    // env.insert("MISE_CONFIG_ROOT".to_string(), root.to_string_lossy().to_string());
    // On Windows, `cmd /c <run>` must receive the command verbatim so inner
    // double quotes survive (#9355). Mirror the hook path: spawn a raw Command
    // with stdout redirected to our stderr handle (duct's stdout_to_stderr) and
    // the full env. Non-cmd shells / Unix fall through to the duct path below.
    #[cfg(windows)]
    {
        if let Some(mut c) = crate::path::cmd_verbatim_command(program, shell_args, run) {
            use std::os::windows::io::AsHandle;
            c.env_clear();
            c.envs(env.iter());
            c.stdout(std::io::stderr().as_handle().try_clone_to_owned()?);
            let status = c.status()?;
            if !status.success() {
                eyre::bail!("watch_files command failed: {status}");
            }
            return Ok(());
        }
    }
    crate::inline_command::optimize_expression(
        cmd(program, args).full_env(&env),
        run,
        &env,
        None,
        direct_enabled,
    )
    .stdout_to_stderr()
    .run()?;
    Ok(())
}

async fn execute_task(
    config: &Arc<Config>,

View on GitHub (pinned to 533346cc37)