Kernel modules cannot load because /lib/modules/.../modules.dep is missing for the running Ubuntu kernel, often after apt-get autoremove removed an older image.

iptables commands on Ubuntu can fail with “No chain/target/match by that name” when required kernel modules such as xt_multiport and xt_comment are missing.

Geordi 1.0 consolidates Rails project commands into a single CLI with command lookup, dependencies, and new setup, update, console, shell, and test workflows.

Reliable test isolation for Rails with Cucumber and RSpec requires cleaning the test database up front and switching strategies for JavaScript-driven examples.

Gem releases are usually tagged in GitHub, letting you switch to a version tag to inspect the README from that release.

Open-source Chrome extension and app for tracking assigned stories across multiple projects in Pivotal Tracker.

jQuery can show or hide form sections based on select values, radio buttons, checkboxes, blank values, and _checked or _unchecked states.

Interactive Ruby debugging lets you pause execution, inspect variables and stack frames, and step through code from a shell or RubyMine.

Pasting multi-line text into LibreOffice Calc can unexpectedly capitalize the first character of the last line because AutoCorrect is enabled.

Refile is a Rails gem for file uploads with better direct-to-S3 support than CarrierWave, but on-demand image rendering can increase server load and require caching or a CDN.

Bugs in select-field ordering can make form choices appear in the wrong sequence; a sorting check helps verify ordered and unordered dropdowns behave correctly.

Browser rendering performance can drop when style or DOM changes force costly repainting and layout recalculation across large parts of the page.

Materialized views in PostgreSQL provide precomputed query results for faster reads; Sequel can map them cleanly for ORM-based applications.

Find a starred GitHub repository again when the name is forgotten. Astral offers split-screen browsing with README previews for starred repos.

Firefox blocks back navigation to POST results with a “Document expired” page, which can disrupt Selenium tests that need to verify recovery from this browser protection.

ImageMagick cropping can preserve aspect ratio by default, and ! forces exact dimensions when a fixed-size image is needed.

Country flag icons for inline and block display with CSS classes, useful for language selectors, location labels, and compact visual markers.

Address data is full of edge cases that break naive assumptions about location, format, and identity. Postal and street addresses often vary by country, purpose, and delivery system.

Quick RSpec-to-Jasmine 2 reference for matching expectations and mock assertions when switching test style; Jasmine 1.x uses different syntax.

Browser navigation during pushState or replaceState tests can leave Jasmine on the wrong URL and break test reruns. Saving and restoring the location keeps the suite on the spec page.

Jasmine DOM testing is easier with matchers like toBeVisible() and toHaveCss(css), plus fixture loading for temporary HTML setup and cleanup.

Native Ruby HTTP client setup can fail when the libcurl development package is missing. Installing the curl headers on Ubuntu 14.04 allows typhoeus to build and install.

Parallel Selenium features can time out when Capybara waits too little for browser-server interactions; a support file increases patience for @javascript scenarios.