Error categories
972 documented errors grouped into 57 categories. Each category page includes an authored guide to debugging that whole class of problem.
- AI 35Rate limits, context windows, GPU memory and model-serving failures.
- Ansible 10Unreachable hosts, become passwords, undefined variables and Jinja2 failures.
- API 14Auth headers, payload limits, versioning, idempotency and webhook signatures.
- Apple 10Command line tools, dyld, Homebrew permissions, notarisation and Keychain.
- Auth 11OIDC, SAML, Auth0, Okta, Keycloak, passkeys and MFA failures.
- BigData 11Spark, Kafka, Airflow, Snowflake, Flink and Databricks failures.
- C# 12NuGet restore, null references, EF Core migrations, async deadlocks and Blazor interop.
- C++ 11Segfaults, linker errors, memory corruption and template deduction failures.
- Caching 10Cache stampedes, stale content, Varnish and CloudFront failures.
- CI/CD 18GitHub Actions, GitLab CI, Jenkins, CircleCI: permissions, runners and resource limits.
- Client 21CORS, mixed content, module resolution, memory limits and framework runtime errors.
- Cloud 25IAM permissions, quotas, service limits and credential failures.
- Dart 10Null safety, pub version solving and build toolchain problems.
- Database 41Connections, deadlocks, constraints, replication and memory limits.
- DNS 10NXDOMAIN, SERVFAIL, timeouts, propagation and delegation problems.
- Docker 27Daemon connectivity, disk space, image pulls, ports and architecture mismatches.
- Elixir 9GenServer timeouts, supervision failures and Mix compilation problems.
- Email 8Delivery failures, relay denial, authentication, SPF, DKIM and DMARC.
- Frontend 23Hydration mismatches, bundler resolution, layout shift and font loading.
- Git 20Merge conflicts, rejected pushes, detached HEAD, LFS and repository corruption.
- Go 19Nil map assignment, concurrent map access, context cancellation and deadlocks.
- GraphQL 13Validation, depth limits, N+1 queries and fragment problems.
- gRPC 10Status codes, deadlines, message limits, TLS and HTTP/2 transport failures.
- HTTP 494xx client errors, 5xx server errors, redirects, headers and protocol problems.
- ICMP 23Destination unreachable, time exceeded, fragmentation needed and redirects.
- Ingress 8404 default backend, missing TLS secrets, IngressClass and path matching.
- Java 19Class loading, dependency resolution, connection pools and JVM version mismatches.
- JavaScript 42npm resolution, async pitfalls, hydration, memory limits and runtime type errors.
- Kubernetes 34CrashLoopBackOff, ImagePullBackOff, OOMKilled, RBAC, scheduling and storage.
- Logging 9Log4j, Logback, Fluentd, Logstash and CloudWatch ingestion problems.
- MessageQueue 14Kafka, RabbitMQ, SQS, NATS and Celery: lag, rebalancing and poison messages.
- Mobile 17Gradle, CocoaPods, Xcode signing, Metro bundler and toolchain mismatches.
- Monitoring 12Prometheus scrapes, Grafana data sources, OpenTelemetry exporters and agent failures.
- Network 35Refused connections, timeouts, resets, MTU problems and port exhaustion.
- Performance 6GC pauses, thread pool starvation and event loop blocking.
- PHP 11Memory limits, execution timeouts, autoloading, Composer and PDO connections.
- Proxy 17nginx, Envoy, HAProxy, Traefik, Caddy and Cloudflare upstream failures.
- Python 35Imports, virtual environments, encoding, concurrency and dependency conflicts.
- Regex 8Catastrophic backtracking, back references, escaping and engine differences.
- Ruby 11Bundler, migrations, native extensions, encoding and asset compilation.
- Rust 19Borrow checker, ownership moves, trait bounds and lifetime mismatches.
- Scala 6Dependency resolution, binary compatibility and type inference failures.
- Security 25JWT validation, CSRF, OAuth grants, SELinux, SSH host keys and CSP.
- Serverless 11Lambda timeouts, package size limits, VPC networking and cold starts.
- Shell 13Command not found, permissions, quoting, expansion and Makefile syntax.
- Storage 13S3 permissions, NFS mounts, quotas, signed URLs and volume attachment.
- Svelte 10Store subscriptions, load functions and server/client boundaries.
- System 26Disk space, systemd units, file descriptors, OOM killer and scheduled jobs.
- Terraform 18State locks, provider auth, drift, dependency cycles and plan-time unknowns.
- Testing 18Jest, pytest, JUnit, Cypress and Playwright: fixtures, snapshots and timeouts.
- TLS 24Untrusted authorities, expiry, hostname mismatch, chains and cipher negotiation.
- TypeScript 19Assignability, missing declarations, strict null checks and generic constraints.
- Virtualization 8VirtualBox, VMware, Hyper-V, WSL, KVM and hypervisor conflicts.
- Web3 7Gas estimation, nonce management and reverted transactions.
- WebAssembly 7Compile errors, memory bounds and host binding mismatches.
- WebServer 10nginx, Apache, IIS and Caddy: binding, permissions, rewrites and TLS.
- Windows 10Installer failures, missing runtimes, update errors and permission problems.
Looking for something specific?
Search the full database or browse the complete A-Z index.