GitHub Actions Failure Debugging: Common Root Causes

GitHub Actions failures are the #1 blocker to team velocity. Most failures follow predictable patterns that AI can recognize instantly.

Failure 1: Dependency Installation Failed

Usually: npm install, pip install, or cargo build fails because a dependency is yanked or incompatible.

AI detection: Scans for "E404", "401 Unauthorized", "version constraint" error patterns.

Fix: Pin compatible versions, use lock files, or check if the dependency was removed.

Failure 2: Test Timeout

A test hangs indefinitely, causing the job to time out after 360 seconds.

AI detection: Identifies the test that timed out and suggests either making it async or increasing timeout.

Fix: Add timeouts to tests, make slow tests async, or run them in parallel.

Failure 3: Out of Disk Space

Build artifacts or Docker layers consume all 14GB available in the runner.

AI detection: Looks for "No space left on device" and suggests cleanup steps.

Fix: Remove old build artifacts, use smaller base images, or split build into multiple jobs.

Failure 4: Secret or Token Invalid

A deploy or release step fails because a GitHub token, API key, or password expired.

AI detection: Identifies authentication failures and suggests checking secrets.

Fix: Rotate the secret or regenerate the token in GitHub Settings.

Failure 5: Flaky Test

A test fails intermittently due to race conditions, timing, or external service flakiness.

AI detection: If a test passes on retry, marks it as flaky and suggests adding retry logic.

Fix: Make tests deterministic, add retries, or mock external services.