Capistrano can fail with net/ssh load errors or an Net::SSH::KnownHosts::SUPPORTED_TYPE constant error when paired with net-ssh 2.5.1. Upgrading to 2.5.2 restores compatibility.

MySQL 5.1 can use the faster InnoDB Plugin instead of the built-in engine, improving performance without changing the file format.

Haml inserts unwanted spaces around inline links, leaving punctuation separated from the anchor. Several workarounds avoid the gap without adding a helper.

beginning_of_day and end_of_day on Date and DateTime ignore Rails 2 time zones, so database queries can hit the wrong records.

Routing a dotted path can break Rails format detection, leaving format as html despite an XML constraint. Matching the route without the extension preserves the intended xml format.

Removing duplication often means finding repeated concepts rather than identical lines, since similar code can hide different intent and reuse can create false matches.

Integrating cross-cutting concerns in Ruby can reduce duplication and keep logging, security, and other shared behavior separate from core business logic.

Checking whether an Ubuntu or Debian system is 32-bit or 64-bit helps match software and troubleshoot compatibility. uname -m reveals the machine architecture.

Rails fails to start when the rails executable points at a missing or half-installed gem set, often after an RVM mismatch or interrupted install.

Rails console sessions can exercise routes, requests, and helpers without running the full app in a browser.

OCRA packages Ruby source into a self-running Windows executable containing the interpreter, code, and dependencies.

RubyMine can reopen on the wrong Ubuntu monitor after moving the window. Keeping the main window unmaximized once lets it remember the preferred screen.

DTAUS and DTAZV remain common German bank transfer formats despite their obsolete floppy-disk origins. king_dtaus generates the required transfer text for banking software.

rspec_candy packages reusable RSpec helpers as a gem, making setup and updates easier for specs that need shared test utilities.

CSS pseudo-elements :before and :after do not render on img elements in browsers, so generated content cannot be added directly to images.

Use a separate Chrome build for Selenium tests by pointing Selenium::WebDriver::Chrome.path at a binary from an environment variable, while keeping your normal browser untouched.

Set browser locale in Selenium tests by configuring intl.accept_languages in a Chrome or Firefox profile, so apps render and negotiate language consistently.

Upload files with a polished interface, progress feedback, previews, multi-file selection, and drag-and-drop support. Bootstrap-based by default, with a jQuery UI variant available.

Buttons and links can look misaligned even with identical CSS because their default box models differ. Setting display, box-sizing, height, and line-height makes them line up.

Testing web apps at mobile-like sizes or with a custom browser identity reveals layout and behavior bugs before release.

window.history lets web apps move backward and forward through browsing sessions and update the history stack with HTML5.

Embedding Bing maps can fail with p_elSource.attachEvent is not a function; disabling Firebug or using another browser avoids the JavaScript error.