Hmbown/CodeWhale · error

125

125

Error message

lane child stdout was not piped

What it means

Post-spawn sanity check in run_lane_log_proxy: although stdout was configured as Stdio::piped before spawning the lane child, taking the pipe from the Child returned None. This indicates a runtime/API mismatch in how the child's stdout was set up; the proxy fails the lane with a distinct exit code rather than silently dropping log output.

Source

Thrown at crates/lane/src/runtime.rs:481

        Vec::new()
    };

    let mut child_command = Command::new(&command[0]);
    child_command.args(&command[1..]);
    child_command.envs(environment);
    child_command.stdout(Stdio::piped()).stderr(Stdio::piped());
    let mut child = match child_command.spawn() {
        Ok(child) => child,
        Err(error) => {
            return fail(
                anyhow::Error::from(error).context(format!("spawn lane child command {command:?}")),
                127,
            );
        }
    };
    let stdout = match child.stdout.take() {
        Some(stdout) => stdout,
        None => return fail(anyhow::anyhow!("lane child stdout was not piped"), 125),
    };
    let stderr = match child.stderr.take() {
        Some(stderr) => stderr,
        None => return fail(anyhow::anyhow!("lane child stderr was not piped"), 125),
    };
    let stdout_log = log_path.clone();
    let stderr_log = log_path.clone();
    let stdout_thread = thread::spawn(move || stream_child_output(stdout, stdout_log, "stdout"));
    let stderr_thread = thread::spawn(move || stream_child_output(stderr, stderr_log, "stderr"));

    let status = match child.wait() {
        Ok(status) => status,
        Err(error) => {
            return fail(
                anyhow::Error::from(error).context(format!("wait for lane child {command:?}")),
                LANE_PROXY_FAILURE_EXIT_CODE,
            );
        }

View on GitHub (pinned to 0c42157ee5)

Solutions

1. Retry the lane; rare std implementation quirks can lose the pipe handle
2. Verify the spawned program is not itself closing/redirecting the inherited descriptors in a way that breaks the contract
3. Update codewhale if a std/OS regression is suspected
4. Inspect the lane log and exit receipt written by the proxy for correlated failures

When it happens

Trigger: Thrown at crates/lane/src/runtime.rs:481 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Hmbown/CodeWhale@0c42157ee5 (2026-08-20). Data as JSON: /api/errors/1180767707da3fd1. Report an issue: GitHub.