DIYgod/RSSHub · warning · Error

Unknown host

Error message

Unknown host: ${url.host}

What it means

Thrown by the Maonan district government route inside a cache.tryGet callback when processing individual article links. After extracting article URLs from the list page, each link's URL host is checked in a switch statement. Only 'mp.weixin.qq.com' and 'www.maonan.gov.cn' have handlers. Any other host triggers this error.

Solutions

  1. Inspect the article list page to identify what new hosts are appearing in links
  2. Add a new case to the switch statement in the cache.tryGet callback for the new host
  3. If the links are non-article navigation, tighten the list CSS selector to exclude them
  4. Consider making the error non-fatal by returning a partial item instead of throwing, to avoid breaking the entire feed

Example fix

// before
default:
    throw new Error(`Unknown host: ${url.host}`);

// after (graceful degradation — skip unknown hosts instead of failing the entire feed)
default:
    return {
        title: $item.text(),
        description: `Content from ${url.host} is not supported`,
        pubDate,
        link,
        author: url.host,
    };
Defensive patterns

Strategy: try-catch

Type guard

const SUPPORTED_HOSTS = new Set(['mp.weixin.qq.com', 'www.maonan.gov.cn']);
function isSupportedHost(url: URL): boolean {
    return SUPPORTED_HOSTS.has(url.host);
}

Try / catch

// Inside the Promise.all map, catch per-item errors instead of failing the feed:
const items = await Promise.all(
    list.map(async (i, item) => {
        try {
            // ... existing logic
        } catch (e) {
            if (e.message.includes('Unknown host')) {
                return null; // skip unsupported hosts gracefully
            }
            throw e;
        }
    })
);
const validItems = items.filter(Boolean);

Prevention

When it happens

Trigger: The article list page (www.maonan.gov.cn/{id}/) contains links whose host is neither mp.weixin.qq.com (WeChat articles) nor www.maonan.gov.cn (government site articles). This could be an external redirect, a CDN link, or a new subdomain. The error is thrown inside a Promise.all map, so it will reject the entire feed generation.

Common situations: The Maonan government site added links to a new domain or subdomain (e.g., a new content management system); external partner links appear in the article list; the list CSS selector matches unintended links (e.g., navigation links to other gov.cn subdomains).

Related errors

AI-assisted analysis of DIYgod/RSSHub@bed535e087 (2026-08-12). Data as JSON: /api/errors/e900aebd94a1a96d. Report an issue: GitHub.

Appendix: source

Thrown at lib/routes/gov/maonan/maonan.ts:154

                            case '/zcjdpt':
                                return {
                                    title: content('meta[name="ArticleTitle"]').attr('content')!,
                                    description: content('.wrap').html(),
                                    pubDate,
                                    link,
                                    author: content('meta[name="ContentSource"]').attr('content') === '本网' ? '茂名市茂南区人民政府网' : content('meta[name="ContentSource"]').attr('content'),
                                };
                            default:
                                return {
                                    title: content('.newsContainer_title').text(),
                                    description: content('.newsContainer_text').html(),
                                    pubDate,
                                    link,
                                    author: content('.author').text().trim() === '本网' ? '茂名市茂南区人民政府网' : content('.author').text().trim(),
                                };
                        }
                    default:
                        throw new Error(`Unknown host: ${url.host}`);
                }
            });
        })
    );

    return {
        title: `茂名市茂南区人民政府 - ${name}`,
        link: `${host}/${id}`,
        item: items,
    };
}

View on GitHub (pinned to bed535e087)