Understanding CI Failures

CI failures aren't mysterious. Learn to read them.

Common CI Jobs

✓ Tests
✓ Linting
✓ Type Checking
✓ Coverage
✓ Performance Benchmarks
✓ Security Scanning

Reading Failure Output

JOB: Tests
FAILURE: Test 'get_user_by_id' failed

AssertionError: None != <User object>
File: tests/test_user_service.py:45
    assert result == expected_user

The test expected result to be a User object,
but got None instead.

What to do: Fix the code to return a User object.

Common Failures

Error	Meaning	Fix
Test failed	Code broke expected behavior	Fix the code
Import error	Missing/wrong module	Check imports
Type error	Wrong data type	Fix types
Coverage dropped	Tests don't cover new code	Add tests
Lint failed	Code style violated	Run formatter

Debugging CI

1. Read the exact error
2. Reproduce locally
3. Fix locally
4. Run tests locally
5. Push again
6. Watch CI pass

CI isn't the enemy. It's your safety net. Fix CI failures aggressively.

Linters & CI Logs & Errors