What causes "failed to fetch {description} from {url}" in Hmbown/CodeWhale?

Retry the update later — the release host was persistently returning retryable errors.

failed to fetch from

Error message

failed to fetch {description} from {url}

What it means

After the retry loop in fetch_release_json, if last_error is None (no HTTP-status error was ever recorded), the code falls back to this generic error. This happens when all attempts looped through retryable statuses without storing an error, or defensively when the loop exited without a success or a stored error. It omits status/body because none was captured.

Solutions

Retry the update later — the release host was persistently returning retryable errors.
Check the host's status page for an outage.
Inspect proxy/firewall interception that might return 502/503 for all requests.
Increase visibility by running with verbose logging to see the per-attempt statuses.

Defensive patterns

Strategy: retry

Validate before calling

// probe connectivity to the host before updating
const res = await fetch(baseUrl + '/releases/latest', { method: 'HEAD' });
if (!res.ok) console.error('release host unreachable:', res.status);

Try / catch

match fetch_release_json(url, desc, proxy) {
  Err(e) if e.to_string().ends_with("failed to fetch") || !e.to_string().contains("HTTP") => {
    // persistent upstream failure: back off significantly and retry later
  }
  other => other,
}

Prevention

Check the provider status page before scripted updates.
Add your own backoff wrapper around update commands.
Bypass intercepting proxies that answer every request with 5xx.

When it happens

Trigger: Every attempt returned a retryable failure status (5xx/408/429) and the final attempt's error path stores last_error but the loop structure exits via the fallback line, or no attempt recorded an error before the loop ended.

Common situations: Sustained upstream outage of the release host during an update; a proxy returning retryable 502/503 for every attempt over the whole retry window.

Understand the failure class

Background: 'Something went wrong' / 'Request failed (500)' / 'HTTP error! status: 404' — what failed HTTP requests actually mean and how to find the real cause — this error's family across 28 libraries.

Related errors

AI-assisted analysis of Hmbown/CodeWhale@73e0f67d83 (2026-09-22). Data as JSON: /api/errors/e56f919a69dd7051. Report an issue: GitHub.

Appendix: source

Thrown at crates/cli/src/update.rs:1438

            Ok((status, body)) if status.is_success() => return Ok(body),
            Ok((status, body)) => {
                let error =
                    anyhow!("failed to fetch {description} from {url}: HTTP {status}\n{body}");
                if should_retry_http_status(status) && attempt < UPDATE_HTTP_ATTEMPTS {
                    last_error = Some(error);
                    sleep_before_update_retry(attempt);
                    continue;
                }
                return Err(error);
            }
            Err(error) if attempt < UPDATE_HTTP_ATTEMPTS => {
                last_error = Some(error);
                sleep_before_update_retry(attempt);
            }
            Err(error) => return Err(error),
        }
    }
    Err(last_error.unwrap_or_else(|| anyhow!("failed to fetch {description} from {url}")))
}

fn should_retry_http_status(status: reqwest::StatusCode) -> bool {
    status.is_server_error()
        || status == reqwest::StatusCode::REQUEST_TIMEOUT
        || status == reqwest::StatusCode::TOO_MANY_REQUESTS
}

fn sleep_before_update_retry(attempt: usize) {
    std::thread::sleep(Duration::from_millis(
        UPDATE_HTTP_RETRY_DELAY_MS * attempt as u64,
    ));
}

fn fetch_latest_release_from_url(url: &str, proxy: Option<&Proxy>) -> Result<Release> {
    let body = fetch_release_json(url, "release info", proxy)?;
    let release: Release = serde_json::from_str(&body).with_context(|| {
        format!("failed to parse release JSON from GitHub API. Response: {body}")

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