156 articles
RSSHow to fix Fastify issues — route 404 from plugin encapsulation, reply already sent, FST_ERR_VALIDATION, request.body undefined, @fastify/cors, hooks not running, and TypeScript type inference.
How to fix Apache Kafka issues — consumer not receiving messages, auto.offset.reset, Docker advertised.listeners, max.poll.interval.ms rebalancing, MessageSizeTooLargeException, and KafkaJS errors.
How to fix Better Auth issues — server and client setup, email/password and OAuth providers, session management, middleware protection, database adapters, and plugin configuration.
How to fix BullMQ issues — queue and worker setup, Redis connection, job scheduling, retry strategies, concurrency, rate limiting, event listeners, and dashboard monitoring.
How to fix GraphQL Yoga issues — schema definition, resolver patterns, context and authentication, file uploads, subscriptions with SSE, error handling, and Next.js integration.
How to fix LangChain.js issues — model setup, prompt templates, RAG with vector stores, conversational memory, structured output, tool agents, and streaming with LangChain Expression Language.
How to fix next-safe-action issues — action client setup, Zod schema validation, useAction and useOptimisticAction hooks, middleware, error handling, and authorization patterns.
How to fix pdf-lib issues — creating PDFs from scratch, modifying existing PDFs, embedding fonts and images, form filling, merging documents, and browser and Node.js usage.
How to fix Pothos GraphQL schema builder issues — type-safe schema definition, object and input types, Prisma plugin, relay connections, auth scope plugin, and schema printing.
How to fix Pusher real-time issues — client and server setup, channel types, presence channels, authentication endpoints, event binding, connection management, and React integration.
How to fix Sharp image processing issues — native binary installation, resize and convert operations, Next.js image optimization, Docker setup, serverless deployment, and common platform errors.
How to fix Stripe issues in Node.js and Next.js — Checkout Sessions, webhook signature verification, subscription lifecycle, customer portal, price management, and idempotent API calls.
How to fix Supertest HTTP testing issues — Express and Fastify setup, async test patterns, authentication headers, file uploads, JSON body assertions, and Vitest/Jest integration.
How to fix Trigger.dev issues — task definition and triggering, dev server setup, scheduled tasks with cron, concurrency and queues, retries, idempotency, and deployment to Trigger.dev Cloud.
How to fix ts-rest issues — contract definition, type-safe client and server setup, Zod validation, Next.js App Router integration, error handling, and OpenAPI generation.
How to fix Auth.js and NextAuth.js issues — OAuth provider setup, session handling in App Router and Pages Router, JWT vs database sessions, middleware protection, and credential provider configuration.
How to fix Effect issues — running effects with Effect.runPromise, Layer and service dependency injection, error channel types, Fiber concurrency, Schema validation, and common TypeScript errors.
How to fix Inngest issues — function and event setup, step orchestration, retries and error handling, cron scheduling, concurrency control, fan-out patterns, and local development with the Dev Server.
How to fix jose JWT issues — signing and verifying tokens with HS256 and RS256, JWK and JWKS key handling, token expiration, claims validation, and edge runtime compatibility.
How to fix Neon Postgres issues — connection string setup, serverless HTTP driver vs TCP, database branching, connection pooling, Drizzle and Prisma integration, and cold start optimization.
How to fix Nitro server engine issues — route handlers, middleware, storage with unstorage, caching, WebSocket support, deployment presets for Cloudflare Workers, Vercel, and Node.js.
How to fix Payload CMS issues — collection and global config, access control, hooks, custom fields, REST and GraphQL APIs, Next.js integration, and database adapter setup.
How to fix React Email and Resend issues — email template components, inline styles, Resend API integration, preview server, attachments, and email client compatibility.
How to fix SST (Serverless Stack) issues — resource configuration with sst.config.ts, linking resources to functions, local dev with sst dev, database and storage setup, and deployment troubleshooting.
How to fix Turso database issues — libsql client setup, connection URLs and auth tokens, embedded replicas for local-first apps, schema migrations, Drizzle ORM integration, and edge deployment.
How to fix Upstash issues — Redis REST client setup, rate limiting with @upstash/ratelimit, QStash message queues, Kafka topics, Vector search, and edge runtime integration.
How to fix Wrangler and Cloudflare Workers issues — wrangler.toml configuration, KV and D1 bindings, R2 storage, environment variables, local dev with Miniflare, and deployment troubleshooting.
How to fix Convex backend issues — query/mutation/action patterns, schema validation, real-time reactivity, file storage, auth integration, and common TypeScript type errors.
How to fix date-fns issues — timezone handling with date-fns-tz, parseISO vs new Date, locale import and configuration, DST edge cases, v3 ESM migration, and common format pattern mistakes.
How to fix Docker secrets — BuildKit secret mounts in Dockerfile, docker-compose secrets config, runtime vs build-time secrets, environment variable alternatives, and verifying secrets don't leak into image layers.
How to fix Hono framework issues — routing order, middleware chaining, Hono RPC type inference, Cloudflare Workers bindings, validator integration, and runtime compatibility.
How to fix HTMX issues — attribute syntax, target and swap strategies, out-of-band swaps, event handling, CSP configuration, response headers, and debugging HTMX requests.
How to fix Kysely query builder issues — database interface definition, dialect setup, type-safe joins and subqueries, migration runner, kysely-codegen for generated types, and common TypeScript errors.
How to fix Lucia auth issues — adapter setup, session validation in middleware, cookie configuration, OAuth provider integration, Next.js App Router setup, and Lucia v3 migration.
How to fix Nuxt 3 issues — useFetch vs $fetch, server routes in server/api, composable SSR rules, useAsyncData, hydration errors, and Nitro configuration problems.
How to fix Python packaging issues — pyproject.toml setup, build backends (setuptools/hatchling/flit), wheel vs sdist, editable installs, package discovery, and twine upload to PyPI.
How to fix Remix issues — loader and action setup, nested route outlet, useLoaderData typing, error boundaries, defer with Await, and common React Router v7 migration problems.
How to fix Supabase issues — Row Level Security policies, realtime subscriptions, storage permissions, auth session with Next.js, edge functions, and common client configuration mistakes.
How to fix SvelteKit issues — load function data flow, +page.server.ts vs +page.ts, form actions with use:enhance, hooks.server.ts, SSR vs CSR mode, and common routing mistakes.
How to fix Swift concurrency issues — async/await in non-async context, Task creation, actor isolation violations, MainActor UI updates, structured concurrency, and Sendable errors.
How to fix AWS Lambda Layer issues — directory structure, runtime compatibility, layer ARN configuration, dependency conflicts, size limits, and container image alternatives.
How to fix AWS SQS issues — visibility timeout, message not delivered, duplicate messages, Dead Letter Queue configuration, FIFO queue ordering, and Lambda trigger problems.
How to fix Bun runtime issues — Node.js API compatibility, native addons (node-gyp), Bun.serve vs Node http, bun test differences from Jest, and common package incompatibilities.
How to fix Celery Beat issues — beat scheduler not starting, tasks not executing on schedule, timezone configuration, database scheduler, and running beat with workers.
How to fix Docker Compose healthcheck issues — depends_on condition service_healthy, healthcheck command syntax, start_period, custom health scripts, and debugging unhealthy containers.
How to fix Drizzle ORM issues — schema definition, drizzle-kit push vs migrate, relation queries with, transactions, type inference, and common PostgreSQL/MySQL configuration problems.
How to fix Express middleware issues — middleware execution order, error-handling middleware signature, async error propagation with next(err), and common middleware misconfigurations.
How to fix Go testing issues — test function naming, table-driven tests, t.Run subtests, httptest, testify assertions, and common go test flag errors.
How to fix gRPC errors — UNAVAILABLE connection errors, DEADLINE_EXCEEDED, UNIMPLEMENTED, TLS setup, interceptors for error handling, and status code mapping.
How to fix Java record issues — compact constructor validation, custom accessor methods, Jackson serialization, inheritance restrictions, and when to use records vs regular classes.
How to fix Kotlin Flow issues — cold vs hot flows, collectLatest vs collect, StateFlow and SharedFlow setup, lifecycle-aware collection in Android, and common Flow cancellation problems.
How to fix Kotlin sealed class issues — when exhaustiveness, sealed interface vs class, subclass visibility, Result pattern, and sealed classes across modules.
How to fix MySQL replication issues — SHOW REPLICA STATUS errors, relay log corruption, GTID configuration, replication lag, skipping errors, and replica promotion.
How to fix OpenTelemetry issues — SDK initialization order, auto-instrumentation setup, OTLP exporter configuration, context propagation, and missing spans in Node.js, Python, and Java.
How to fix PostgreSQL JSONB query issues — -> vs ->> operators, @> containment, GIN indexes, type casting, array queries, and indexing strategies for JSONB columns.
How to fix PostgreSQL Row Level Security (RLS) issues — enabling RLS, policy expressions, BYPASSRLS role, SET ROLE, current_user vs session_user, and Supabase auth.uid() patterns.
How to fix Python context manager issues — @contextmanager generator, __enter__ and __exit__, exception handling inside with blocks, async context managers, and common pitfalls.
How to fix Python Protocol class issues — structural subtyping vs nominal typing, runtime_checkable, Protocol inheritance, TypeVar constraints, and common mypy/pyright errors with Protocol.
How to fix Python subprocess issues — capturing stdout/stderr, shell=True risks, Popen vs run, timeout handling, and common subprocess errors explained.
How to fix Redis Cluster errors — MOVED redirects, CROSSSLOT multi-key operations, cluster-aware client setup, hash tags for key grouping, and failover handling.
How to fix Rust error handling issues — the ? operator, From trait for error conversion, thiserror for custom errors, anyhow for applications, and Box<dyn Error> pitfalls.
How to fix Spring Boot test issues — @SpringBootTest vs test slices, MockMvc setup, @MockBean vs @Mock, test context caching, and common test configuration mistakes.
How to fix Spring Boot @Cacheable issues — @EnableCaching missing, self-invocation bypass, key generation, TTL configuration, cache eviction, and Caffeine vs Redis setup.
How to fix tRPC issues — router setup, type inference across packages, context injection, middleware, error handling, and common tRPC v10/v11 configuration mistakes.
How to fix Zod schema validation issues — parse vs safeParse, transform and preprocess, refine for cross-field validation, discriminatedUnion, error formatting, and common schema mistakes.
How to fix docker-compose.override.yml not being applied — file naming, merge behavior, explicit file flags, environment-specific configs, and common override pitfalls.
How to fix FastAPI BackgroundTasks — task not executing, dependency injection in tasks, error handling, Celery for heavy tasks, and lifespan-managed background workers.
How to fix Go generics errors — type constraints, interface vs constraint, comparable, union types, type inference failures, and common generic function pitfalls.
How to fix Kubernetes HorizontalPodAutoscaler issues — metrics-server not installed, CPU requests not set, unknown metrics, scale-down delay, custom metrics, and KEDA.
How to fix MongoDB aggregation pipeline issues — $lookup field matching, $unwind on missing fields, $match placement, $group _id, type mismatches, and pipeline debugging.
How to fix NestJS Swagger UI not displaying — SwaggerModule setup, DocumentBuilder, decorators not appearing, guards blocking the docs route, and Fastify vs Express differences.
How to fix Node.js stream issues — pipe and pipeline errors, backpressure handling, Transform streams, async iteration, error propagation, and common stream anti-patterns.
How to fix Python pathlib issues — TypeError with string concatenation, path joining, glob patterns, reading files, cross-platform paths, and migrating from os.path.
How to fix Spring Data JPA query issues — JPQL vs native SQL, derived method naming, @Modifying for updates, pagination, projections, and LazyInitializationException.
How to fix AWS Lambda environment variables not available — Lambda console config, CDK/SAM/Terraform setup, secrets from SSM Parameter Store, encrypted variables, and local testing.
How to fix AWS S3 CORS errors — S3 bucket CORS configuration, pre-signed URL CORS, CloudFront CORS headers, OPTIONS preflight requests, and presigned POST uploads.
How to fix Docker ARG and ENV variable issues — build-time vs runtime scope, ARG before FROM, multi-stage build variable passing, secret handling, and .env file patterns.
How to fix Docker HEALTHCHECK failures — command syntax, curl vs wget availability, start period, interval tuning, health check in docker-compose, and debugging unhealthy containers.
How to fix Express rate limiting not working — middleware order, trust proxy for reverse proxies, IP detection, store configuration, custom key generation, and bypassing issues.
How to fix Go channel deadlocks — unbuffered vs buffered channels, missing goroutines, select statements, closing channels, sync primitives, and detecting deadlocks with go race detector.
How to fix Go error handling — errors.Is vs ==, errors.As for type extraction, fmt.Errorf %w for wrapping, sentinel errors, custom error types, and stack traces.
How to handle Go panics correctly — recover() placement, goroutine panics, HTTP middleware recovery, defer ordering, distinguishing panics from errors, and when not to use recover.
How to fix GraphQL error handling — error extensions, partial data with errors, Apollo formatError, custom error classes, client-side error detection, and network vs GraphQL errors.
How to fix Kotlin coroutines not executing — CoroutineScope setup, dispatcher selection, structured concurrency, cancellation handling, blocking vs suspending calls, and exception propagation.
How to fix Kotlin coroutine cancellation issues — scope lifecycle, SupervisorJob, CancellationException handling, structured concurrency, viewModelScope, and cooperative cancellation.
How to fix Laravel queue jobs not running — queue worker not started, wrong connection config, failed jobs, job timeouts, horizon setup, and database vs Redis queue differences.
How to fix MongoDB schema validation errors — $jsonSchema rules, required fields, type mismatches, enum constraints, bypassing validation for migrations, and Mongoose schema conflicts.
How to fix MySQL full-text search issues — FULLTEXT index creation, minimum word length, stopwords, boolean mode vs natural language mode, InnoDB vs MyISAM, and LIKE fallback.
How to fix NestJS dependency injection errors — module imports, provider exports, circular dependencies, dynamic modules, and the most common 'can't resolve dependencies' patterns.
How to fix NestJS ValidationPipe not validating requests — global pipe setup, class-transformer, whitelist and transform options, custom validators, and DTO inheritance issues.
How to fix nginx load balancing issues — upstream block configuration, health checks, least_conn vs round-robin, sticky sessions, upstream timeouts, and SSL termination.
How to fix PHP session variables that don't persist between requests — session_start() placement, cookie settings, session storage, shared hosting, and session fixation security.
How to fix Prisma connection pool errors — pool size configuration, connection leaks, serverless deployments, singleton pattern, query timeout, and pgBouncer integration.
How to fix asyncio.gather error handling — return_exceptions parameter, partial failures, task cancellation propagation, TaskGroup alternatives, and exception isolation patterns.
How to fix Python decorator issues — functools.wraps, decorator factories with arguments, class decorators, stacking order, async function decorators, and common pitfalls.
How to fix Python mypy type errors — incompatible types in assignment, missing return type, Optional handling, TypedDict, Protocol, overloads, and common mypy configuration mistakes.
How to fix Pydantic v2 validation errors — required fields, type coercion, model_validator, custom validators, extra fields config, and migrating from Pydantic v1.
How to fix Rails N+1 queries — includes vs joins vs preload vs eager_load, Bullet gem detection, avoiding N+1 in serializers and views, and counter caches.
How to fix Ruby Bundler gem version conflicts — Gemfile.lock resolution, platform-specific gems, bundle update strategies, conflicting transitive dependencies, and Bundler version issues.
How to fix Spring @Transactional not rolling back — checked vs unchecked exceptions, self-invocation proxy bypass, rollbackFor, transaction propagation, and nested transactions.
How to fix TypeScript function overload errors — overload signature compatibility, implementation signature, conditional types as alternatives, method overloads in classes, and common pitfalls.
How to fix TypeScript mapped type errors — Partial, Required, Readonly, Record, Pick, Omit, conditional types, template literal types, and distributive behavior.
How to fix AWS Access Denied errors — understanding IAM policies, using IAM policy simulator, fixing AssumeRole errors, resource-based policies, and SCPs blocking actions.
How to fix Docker layer cache being invalidated on every build — Dockerfile instruction order, COPY optimization, ARG vs ENV, BuildKit cache mounts, and .dockerignore.
How to fix FastAPI dependency injection errors — async dependencies, database sessions, sub-dependencies, dependency overrides in tests, and common DI mistakes.
How to find and fix goroutine leaks in Go — detecting leaks with pprof and goleak, blocked channel patterns, context cancellation, and goroutine lifecycle management.
How to fix the Go interface nil trap — understanding non-nil interfaces with nil pointers, detecting the issue, error interface patterns, and designing APIs to avoid the pitfall.
How to fix Go's concurrent map read and write panic — using sync.RWMutex, sync.Map, atomic operations, and structuring code to avoid shared state.
How to fix Kubernetes Secrets not being mounted — namespace mismatches, RBAC permissions, volume mount configuration, environment variable injection, and secret decoding issues.
How to fix MySQL indexes not being used by the query optimizer — EXPLAIN output, implicit conversions, function on columns, composite index order, cardinality issues, and forcing indexes.
How to fix NestJS guards not working — applying guards globally vs controller vs method level, JWT AuthGuard, metadata with Reflector, public routes, and guard execution order.
How to fix NestJS interceptors not being called — global vs controller vs method binding, response transformation, async interceptors, execution context, and interceptor ordering.
How to handle Node.js uncaughtException and unhandledRejection events — graceful shutdown, error logging, async error boundaries, and keeping servers alive safely.
How to fix the N+1 query problem in Prisma — using include and select for eager loading, fluent API pitfalls, DataLoader integration, and query logging to detect N+1 patterns.
How to fix Prisma transaction errors — interactive transactions vs $transaction array, error handling and rollback, nested transactions, timeout issues, and isolation levels.
How to fix Python asyncio event loop blocking — using run_in_executor for sync calls, asyncio.to_thread, avoiding blocking I/O in coroutines, and detecting event loop stalls.
How to fix Python circular import errors — restructuring modules, lazy imports, TYPE_CHECKING guard, dependency injection, and __init__.py import order issues.
How to fix Redis Pub/Sub issues — subscriber not receiving messages, channel name mismatches, connection handling, pattern subscriptions, and scaling with multiple processes.
How to fix Socket.IO CORS errors — server-side CORS configuration, credential handling, polling vs WebSocket transport, proxy setup, and common connection failures.
How to fix TypeScript 'could not find a declaration file for module' errors — installing @types packages, writing custom .d.ts files, module augmentation, and tsconfig paths.
How to fix Celery tasks not executing — worker configuration, broker connection issues, task routing, serialization errors, and debugging stuck or lost tasks.
How to fix Django REST Framework 403 Forbidden and permission denied errors — authentication classes, permission classes, IsAuthenticated vs AllowAny, object-level permissions, and CSRF issues.
How to fix Express async route handlers not passing errors to the error middleware — wrapping async routes, using express-async-errors, global error handlers, and Node.js unhandledRejection events.
How to fix Go context.DeadlineExceeded and context.Canceled errors — setting timeouts correctly, propagating context through call chains, handling cancellation, and debugging which operation timed out.
How to fix the GraphQL N+1 query problem — understanding why it happens, implementing DataLoader for batching, using query complexity limits, and selecting efficient resolver patterns.
How to fix Kubernetes OOMKilled errors — understanding memory limits, finding memory leaks, setting correct resource requests and limits, and using Vertical Pod Autoscaler.
How to diagnose and fix slow MySQL queries — enabling the slow query log, reading EXPLAIN output, adding indexes, fixing N+1 queries, and optimizing JOINs and ORDER BY.
How to fix NestJS circular dependency errors — using forwardRef, restructuring module dependencies, extracting shared services, and understanding the NestJS module system.
How to fix Node.js 'JavaScript heap out of memory' — increasing heap size, finding memory leaks with heap snapshots, fixing common leak patterns, and stream-based processing for large data.
How to fix pandas SettingWithCopyWarning — understanding chained indexing, using .loc correctly, Copy-on-Write in pandas 2.x, and when the warning indicates a real bug vs a false alarm.
How to diagnose and fix slow PostgreSQL queries — reading EXPLAIN ANALYZE output, adding the right indexes, fixing N+1 queries, optimizing joins, and using pg_stat_statements.
How to fix Python logging not displaying messages — log level misconfiguration, missing handlers, root logger vs named loggers, basicConfig not working, and logging in libraries vs applications.
How to fix Terraform state lock errors — understanding lock mechanisms, safely force-unlocking stuck locks, preventing lock conflicts in CI/CD, and using remote backends correctly.
How to fix TypeORM QueryFailedError, entity not found errors, relation issues, missing migrations, and connection configuration problems in Node.js and NestJS applications.
How to fix ECS tasks that fail to start — port binding errors, missing IAM permissions, Secrets Manager access, essential container exit codes, and health check failures.
How to fix Docker Compose networking issues — services can't reach each other by hostname, port mapping confusion, network aliases, depends_on timing, and host vs container port differences.
How to fix Docker multi-stage build errors — COPY --from stage not found, wrong stage name, artifacts not at expected path, and BuildKit caching issues.
How to fix req.body being undefined in Express — missing body-parser middleware, wrong Content-Type header, middleware order issues, and multipart form data handling.
How to fix Flask routes returning 404 — trailing slash redirect, Blueprint prefix issues, route not registered, debug mode, and common URL rule mistakes.
How to fix CORS errors in Flask — installing flask-cors correctly, handling preflight OPTIONS requests, configuring origins with credentials, route-specific CORS, and debugging missing headers.
How to fix Go nil pointer dereference panics — checking for nil before use, nil interface traps, nil map writes, receiver methods on nil, and defensive nil handling patterns.
How to fix Hibernate LazyInitializationException — loading lazy associations outside an active session, fetch join, @Transactional scope, DTO projection, and Open Session in View.
How to fix Linux OOM killer terminating processes — reading oom_kill logs, adjusting oom_score_adj, adding swap, tuning vm.overcommit, and preventing memory leaks.
How to fix CORS errors in Next.js API routes — adding Access-Control headers, handling preflight OPTIONS requests, configuring next.config.js headers, and avoiding common proxy mistakes.
How to fix PostgreSQL 'sorry, too many clients already' error — checking active connections, using connection pooling with PgBouncer, tuning max_connections, fixing ORM pool settings, and finding connection leaks.
How to fix Pydantic ValidationError in Python — missing required fields, wrong types, custom validators, handling optional fields, v1 vs v2 API differences, and debugging complex nested models.
How to fix 'Failed to configure a DataSource: url attribute is not specified' in Spring Boot — adding database properties, excluding DataSource auto-configuration, H2 vs production DB setup, and multi-datasource configuration.
How to fix TypeScript decorators not applying — experimentalDecorators not enabled, emitDecoratorMetadata missing, reflect-metadata not imported, and decorator ordering issues.
How to fix TypeScript enum problems — const enum with isolatedModules, enums not available at runtime, string vs numeric enums, and migrating to union types or as const objects.
How to fix AWS CloudWatch logs not showing up — IAM permissions missing, log group not created, log stream issues, CloudWatch agent misconfiguration, and Lambda log delivery delays.
How to fix Spring Boot circular dependency errors — BeanCurrentlyInCreationException, refactoring to break cycles, @Lazy injection, setter injection, and @PostConstruct patterns.
How to fix Spring Security 403 Forbidden errors — CSRF token missing, incorrect security configuration, method security blocking requests, and how to debug the Spring Security filter chain.
How to fix MongoDB 'not primary' errors when writing to a replica set — read preference misconfiguration, connecting to a secondary, replica set elections, and write concern settings.
How to fix Node.js UnhandledPromiseRejectionWarning and process crashes — why unhandled promise rejections crash Node.js 15+, how to add global handlers, find the source of the rejection, and fix async error handling.
How to fix Python dataclass mutable default errors — why lists, dicts, and sets cannot be default field values, how to use field(default_factory=...), and common dataclass pitfalls with inheritance and ClassVar.
How to fix Python requests hanging forever — why requests.get() ignores timeout, how to set connect and read timeouts correctly, use session-level timeouts, and handle timeout exceptions properly.