Linux CI/CD & Automation Errors: runners, secrets, flaky tests, deploy failures
Working reference for the 10 most common Linux CI/CD pipeline errors. Runner offline (gitlab-runner / github-actions-runner systemctl), secret env var not injected, docker login failures (use ephemeral CI tokens), flaky tests (env vs hardware vs race), build cache miss, disk full on runner, job timeouts, deployment connection refused, git pull auth, Ansible host key verification. Cross-linked to docker, build, and systemd troubleshooting.