Error Handling Reference

Error Handling Reference

Comprehensive guide to errors, causes, and solutions for the aggregating-crypto-news skill.

Error Categories

1. Network Errors

ConnectionError

Message: Connection failed or Failed to establish connection

Cause: No internet connectivity or DNS resolution failure.

Solution:

1. Check internet connection
2. Verify DNS settings
3. Try again after connection is restored
4. Cached data will be used if available

TimeoutError

Message: Request timed out for [source]

Cause: RSS feed server not responding within timeout window.

Solution:

1. Source is automatically skipped
2. Other sources continue to be fetched
3. Cached data used if available for that source
4. Check if source is down: visit URL in browser

Mitigation:

• Default timeout is 10 seconds per source
• Parallel fetching prevents one slow source from blocking others

HTTPError (4xx/5xx)

Message: HTTP 403 Forbidden or HTTP 500 Server Error

Cause: Source blocking requests or server issues.

Solution:

• 403: Source may be blocking automated access
• 404: RSS feed URL has changed
• 5xx: Server-side issue, try later

Note: Aggregator continues with available sources; failed sources are logged.

2. Parse Errors

FeedParseError

Message: Failed to parse feed from [source]

Cause: Malformed RSS/Atom XML that feedparser cannot process.

Solution:

1. Source is skipped
2. Check if source has valid RSS: validate at https://validator.w3.org/feed/
3. Report issue if feed URL has changed

MissingFieldError

Message: Article missing required field: title

Cause: Feed entry lacks required fields (title, link).

Solution:

1. Entry is skipped
2. Other entries from source continue to process
3. No user action needed

DateParseError

Message: Failed to parse date for article

Cause: Non-standard date format in feed entry.

Solution:

1. Article is included without date
2. Recency scoring disabled for that article
3. May appear out of order when sorted by recency

3. Filter Errors

InvalidCoinSymbol

Message: Unknown coin symbol: [symbol]

Cause: User provided unrecognized coin symbol.

Solution:

1. Check spelling (case-insensitive: btc, BTC, Btc all work)
2. Use common symbols: BTC, ETH, SOL, BNB, XRP, ADA, DOGE, etc.
3. Filter will attempt to match anyway against article text

Note: This is a warning, not a fatal error. Filter proceeds.

InvalidCategory

Message: Invalid category: [category]

Cause: User provided category not in allowed list.

Solution: Use one of: market, defi, nft, regulatory, layer1, layer2, exchange, security

NoResultsFound

Message: No articles found matching your criteria

Cause: Filters are too restrictive for current news.

Solution:

1. Relax time window: --period 24h instead of --period 1h
2. Remove coin filter: drop --coin option
3. Lower score threshold: --min-score 0
4. Try different category or remove category filter

Suggested Relaxations:

# If no results with strict filters:
python news_aggregator.py --coin BTC --period 1h --min-score 50

# Try relaxing step by step:
python news_aggregator.py --coin BTC --period 4h    # Longer window
python news_aggregator.py --period 1h --min-score 0  # Lower threshold
python news_aggregator.py --period 4h               # Both relaxed

4. Export Errors

FileWriteError

Message: Failed to write to output file: [path]

Cause: Cannot write to specified path.

Solution:

1. Check directory exists
2. Check write permissions
3. Ensure disk space available
4. Use absolute path if relative fails

InvalidFormat

Message: Invalid output format: [format]

Cause: Unrecognized format option.

Solution: Use one of: table, json, csv

5. Dependency Errors

ImportError: feedparser

Message: Error: feedparser library required

Cause: feedparser package not installed.

Solution:

pip install feedparser

ImportError: requests

Message: Error: requests library required

Cause: requests package not installed.

Solution:

pip install requests

Error Handling Strategy

Graceful Degradation

Full Success (all sources fetched)
     │
     ▼
Partial Success (some sources failed)
     │ → Continue with available data
     │ → Log warnings for failed sources
     │
     ▼
Cached Fallback (network issues)
     │ → Return cached data
     │ → Warn about stale data
     │
     ▼
Complete Failure (no data available)
     │ → Clear error message
     │ → Suggest remediation steps

Behavior by Error Type

Debugging

Enable Verbose Mode

python news_aggregator.py --verbose

Shows:

• Which sources are being fetched
• Cache hits/misses
• Parse results per source
• Filter statistics
• Timing information

Check Individual Source

# Validate RSS feed
curl -s "https://www.coindesk.com/arc/outboundfeeds/rss/" | head -50

# Or use a feed validator
# https://validator.w3.org/feed/check.cgi

Test with Single Source

Edit config/sources.yaml to include only one source for testing.

Error Codes

Reporting Issues

When reporting issues, include:

1. Command executed:

   python news_aggregator.py --verbose [your options]
   

2. Full error output (with --verbose)

3. Environment:

   python --version
   pip list | grep -E "feedparser|requests"
   

4. Network test:

   curl -I https://www.coindesk.com/arc/outboundfeeds/rss/