When Ubuntu Builds Fail on libvips but macOS Does Not
Why a Rails test suite can fail on Ubuntu because of an older native libvips, and how to upgrade it safely without confusing it with the ruby-vips gem.
Tag: ruby
The CI failures that moved every time you reran them
How a moving set of Rails CI flakes exposed shared download state, Selenium stale-node retries, and specs asserting before the browser settled.
Rails Performance from the Metal Up: A Field Guide
A practical Rails performance field guide for diagnosing CPU, IO, GVL, GC, memory, Puma, and container-runtime bottlenecks before choosing a fix.
Production Ruby Debugging: A Progressive Escalation Guide
A progressive escalation guide to debugging Ruby applications in Kubernetes production without restarting: rbspy, kubectl debug, signals, rbtrace, and gdb.
load_async in Rails 8: loading associations concurrently
Rails 8's load_async runs association queries concurrently instead of one after another, and getting it right means sizing your connection pool correctly.
Rails 8.1.1 + connection_pool 3.x: RedisCacheStore boot crash
A keyword-argument mismatch between Ruby 3.4 and connection_pool 3.x breaks RedisCacheStore at Rails 8.1.1 boot, fixed with a patch loaded before initializers run.
Why Using Business Logic for Test Setup Is a Rails Antipattern
Using application services to build test data couples your specs to that business logic, making test suites slow and fragile; Factory Bot traits fix it.
Ruby Debugging in VS Code: Shopify LSP, rdbg, and RSpec
How to wire up VS Code for Ruby debugging with the Shopify Liquid LSP, the rdbg debugger from Ruby's debug gem, and launch configs for RSpec, Minitest, and Cucumber.
Closures, Blocks, and Iterators Across Six Languages
A working comparison of how Python, JavaScript, Ruby, PHP, Rust, and Go implement closures and lazy iteration, with a runnable counter and generator example for each.
Ruby Ractor vs the GVL: When You Get Real Parallelism
How Ruby's Global VM Lock limits threaded CPU-bound code, and how Ractor bypasses it entirely by trading shared memory for message passing.
Nokogiri vs libxml2: Debugging a Dynamic Library Conflict
Why Nokogiri XPath queries failed in Docker but not on an M1 Mac: a libxml2 version mismatch caused by indirect dynamic library loading in Ruby.
Timezone Bugs in Ruby: BST vs UTC in CI and Cron
How British Summer Time breaks Ruby tests, cron schedules, and cloud functions that assume UTC, and how to write timezone-aware specs instead.
编程方法论中的“矛盾”：权衡的艺术 (Ruby 示例)
本文用 Ruby 代码示例，剖析 DRY 与 AHA、YAGNI 与可扩展性设计、继承与组合等几对看似冲突的编程原则，说明该如何在实践中权衡取舍。
Monkey-Patching in PHP vs Ruby: Why One Is an Anti-Pattern
Runtime method overrides work very differently in PHP and Ruby: one has no rollback mechanism, the other builds aliasing and scoping in from the start.
Handling Out-of-Order Updates in Async Rails Workflows
When async updates to the same record can finish in any order, the oldest write can silently overwrite the newest one; here is how to stop that.
Debugging in Ruby, Python, and PHP: byebug, pdb, and Xdebug
Compares Ruby's byebug, Python's pdb, and PHP's Xdebug side by side, with the core commands and a working example for each language.
Retry Strategies in Ruby: Exceptions vs. Conditional Checks
Comparing Ruby retry patterns, exception-based retry, conditional checks, and exponential backoff, and when each keeps performance acceptable.
Testing Non-ASCII Fonts with Prawn and PDF::Inspector
How to debug Unicode font rendering in Ruby's Prawn PDF library and work around PDF::Inspector's limits when testing non-ASCII characters like it.
Ruby readability vs performance: filter_map and a single loop
Ruby's filter_map cuts a multi-pass select/map/uniq chain to one pass, and a plain each loop goes further still when performance actually matters.
Ruby object IDs, anonymous modules, and Rails cache errors
A Rails.cache TypeError on an anonymous module led into Ruby's Marshal restrictions and the relationship between object_id and C-level memory addresses.
Why Kaminari's Anonymous Modules Break Rails Caching
Why Rails caching raises TypeError: can't dump anonymous module with Kaminari-paginated collections, and how to trace and fix the module causing it.
Self-Hosted Whisper: A Speech-to-Text API with Ruby and Kubernetes
How to run OpenAI's Whisper as a self-hosted speech-to-text REST API with Docker, a Ruby client, and a Kubernetes deployment for transcribing audio.
Rufus-Scheduler vs Sidekiq-Scheduler for Ruby Jobs
Comparing rufus-scheduler's in-process polling loop with sidekiq-scheduler's Redis-backed queue to pick the right one for single-process vs distributed apps.
Rufus Scheduler: How Its Main Loop Actually Works
How rufus-scheduler's single-threaded main loop triggers, times out, and runs jobs, and where a timer-based rewrite would scale better.
Rack: The Interface Between Ruby Web Servers and Apps
Rack is the standard interface between Ruby web servers and frameworks, traced here through its middleware stack from request to response.
Integer Overflow and Floating-Point Precision: Ruby vs JS
Why 0.1 + 0.2 doesn't equal 0.3, how Ruby's arbitrary-precision integers avoid overflow, and how JavaScript's BigInt does the same for large integers.
Round Is Not Always What You Expect
Rounding the same float, 2.675, to two decimal places gives different answers in C#, PHP, Go, Python, JavaScript, and Ruby, for concrete reasons.
Upgrading to Rails 7.2: Four Breaking Changes We Hit
Four breaking changes we hit upgrading to Rails 7.2: show_exceptions, array-containment SQL, connection pool locking, and assert_enqueued_email_with.
Ruby's GVL vs Ractor: What Actually Runs in Parallel
Ruby's Global VM Lock serializes threads for CPU-bound work, and Ractor works around it with isolated memory, benchmarked here against threads and processes.
fail vs raise in Ruby: They're the Same Method
Ruby's fail is a plain alias for raise, both dispatch to the same Kernel method, confirmed here in the C source and with an lldb backtrace.
Speeding Up Nested JSON Serialization in Rails
Caching, the Oj gem, eager loading, background jobs, and load_async each cut serialization time for deeply nested Rails associations like classrooms and scores.
delete_all vs destroy_all in Rails: Callbacks and Associations
delete_all skips callbacks and dependent associations while destroy_all runs them, and picking the wrong one silently breaks counter caches and cascades.
Floating-Point Precision in Ruby: Why 0.1 + 0.33 ≠ 0.43
Ruby's 0.1 + 0.33 does not equal 0.43 because of binary floating-point rounding, and Rational, BigDecimal, and tolerance comparisons each fix it differently.
Inspecting Sidekiq Jobs from the Rails Console
Console-ready Ruby snippets to inspect Sidekiq queues, scheduled jobs, retry and dead sets, and currently running workers when the dashboard is not enough.
Rails N+1 Queries: joins vs preload vs eager_load vs includes
What joins, preload, eager_load, and includes actually do in ActiveRecord, shown with real SQL logs, plus the chained calls that quietly bring the N+1 back.
A .irbrc Full of Ruby Debugging and Introspection Helpers
A collection of .irbrc helpers for tracing method calls, logging SQL queries, profiling code, and inspecting Ruby objects during Rails console debugging.
Rails Session Stores: Cookie, ActiveRecord, and Redis
A comparison of Rails session stores: cookie sessions, ActiveRecord, and Redis, including how to share sessions across subdomains and multiple apps.
How to Set a Breakpoint on Devise's current_user Method
Why byebug can't break on Devise's metaprogrammed current_user method, and several ways to debug or patch a method that isn't in your source.
Soft Delete in Rails: Discard vs ActsAsParanoid
A comparison of Discard and ActsAsParanoid, the two common Rails soft-delete gems, and the query and unscope pitfalls each one introduces.
How Rails Loads Your App: Rake, Console, Server, and Tests
What Rails actually loads when you run a rake task, the console, the server, or tests, and how to load rake tasks in each environment when you need them.
Rails unscope: removing default scope conditions
How ActiveRecord's unscope method selectively removes where and order conditions from default scopes, with examples and alternatives like merge and unscoped.