Hmbown/CodeWhale · error

log file missing

Error message

log file missing: {}

What it means

The `codewhale lane log` (tail) command resolves the lane via `LaneRegistry::open_default`, reads `lane.log_path`, and bails if that file does not exist before reading and splitting its content into lines. It is thrown because tailing a non-existent log is indistinguishable from an empty one and would silently show nothing. The error carries the missing path so the user can check the right location.

Solutions

1. Run the lane once so its log file is created, then retry the log command.
2. Verify the path shown in the error exists and matches the lane's configured log_path; fix the lane config if it points elsewhere.
3. If the log was rotated/deleted, restore it or re-register the lane to regenerate the log.
4. Check you are running on the same host/filesystem where the lane actually writes its log (containers, remote workers).

Example fix

// before: tail a lane that never started
codewhale lane log my-lane --tail 50
// error: log file missing: /var/lib/codewhale/lanes/my-lane/log

// after: start the lane first
codewhale lane run my-lane
codewhale lane log my-lane --tail 50

let path = lane.log_path;
if !path.exists() {
    eprintln!("skipping log tail: {} does not exist (lane never run?)", path.display());
    return Ok(());
}

match run_lane_log(&lane_id) {
    Err(e) if e.to_string().contains("log file missing") => eprintln!("lane has no log yet; start it first"),
    Err(e) => return Err(e),
    Ok(v) => println!("{v}"),
}

When it happens

Trigger: Running a lane-log command whose `LaneRegistry::load(&lane_id)` returns a lane whose `log_path` does not exist on disk at invocation time (`!path.exists()`).

Common situations: The lane was registered but never run, the log file was deleted or rotated away, the lane points at a path on another machine/container volume, or a typo in config points the lane at a stale path.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

• already exists; pass --force to overwrite it
• Cannot resolve current binary path
• inline stderr logger panicked
• inline stdout logger panicked
• lane log proxy requires a command

AI-assisted analysis of Hmbown/CodeWhale@73e0f67d83 (2026-09-22). Data as JSON: /api/errors/8226fcc4e3e25153. Report an issue: GitHub.

Appendix: source

Thrown at crates/cli/src/lib.rs:997

                        println!("{attach}");
                        bail!("tmux attach unavailable");
                    }
                }
            } else {
                println!("{attach}");
                Ok(())
            }
        }
        LaneCommand::Logs {
            lane_id,
            follow,
            tail,
        } => {
            let reg = LaneRegistry::open_default()?;
            let lane = reg.load(&lane_id)?;
            let path = lane.log_path;
            if !path.exists() {
                bail!("log file missing: {}", path.display());
            }
            let content = std::fs::read(&path)?;
            let lines: Vec<&[u8]> = content
                .split(|byte| *byte == b'\n')
                .filter(|line| !line.is_empty())
                .collect();
            let start = lines.len().saturating_sub(tail);
            let mut stdout = std::io::stdout().lock();
            for line in &lines[start..] {
                stdout.write_all(String::from_utf8_lossy(line).as_bytes())?;
                stdout.write_all(b"\n")?;
            }
            stdout.flush()?;
            if !follow {
                return Ok(());
            }
            let mut file = std::fs::File::open(&path)?;
            file.seek(std::io::SeekFrom::End(0))?;

View on GitHub (pinned to 73e0f67d83)