Set xterm’s default colors in ~/.Xresources to avoid black text on white backgrounds; xrdb applies the settings to the current X session.

Passenger can fail with a misleading EOF error when the app spawner exits unexpectedly, often because a gem is missing. bundle install usually resolves it.

Paperclip attachment presence validation depends on has_attached_file being declared first; conditional validation with :if also works.

Calc pastes normally overwrite existing spreadsheet cells; inserting clipboard cells instead shifts surrounding cells down or right.

RedCloth can fail to install through Bundler on older GCC toolchains; adding a build flag suppresses warnings during compilation.

Quoted-printable encoding turns = into =3D in development email logs, which can make token values look longer than they are.

A geordi command streamlines safe production releases by comparing master and production, confirming the merge, then pushing and deploying migrations with Capistrano.

Printed spreadsheet areas in LibreOffice Calc can be adjusted by moving page breaks in preview and changing sheet scaling settings.

Bundler 1.1 can trigger a misleading Cucumber warning during test runs; disabling automatic loading for cucumber-rails removes it without moving the gem into a test group.

Plain-text task lists stay portable across devices and apps, with Dropbox sync, mobile editing, and a CLI for quick task management; nesting is not supported.

validates_acceptance_of silently skips nil attributes, so a missing checkbox or typo can leave acceptance unchecked; a boolean field with validates_presence_of is safer.

New branches pushed to origin do not track a remote branch by default, so git pull cannot follow their upstream; git push -u sets the tracking reference immediately.

Constrain a Rails route to a single response format such as XML when one URL must serve only that representation.

\G in the MySQL shell switches query output to a vertical format, which is easier to read for wide rows or long text fields.

Use Tab and Shift+Tab in regular textareas to indent or outdent code for in-browser editing of HTML, CSS, JavaScript, or server-side languages.

Find the most frequent string in an array without failing on empty input; the approach uses grouping and returns the first value from the largest group.

JavaScript key binding library for handling single keys and key combinations in web apps.

Filter MySQL connections to hide idle sessions and focus on active or slow queries, with flexible sorting and column selection via information_schema.processlist.

Temporary monkey patch for older Capybara and selenium-webdriver versions to suppress repeated deprecation warnings from Selenium::WebDriver::Element#select.

VirtualBox NAT guests can reach the host at 10.0.2.2; vbox.srv is the matching hostname for shared folders and host web server access.

Capybara's save_and_open_page files can clutter the Rails root when debugging Cucumber scenarios. Set Capybara.save_and_open_page_path to store them elsewhere.

Connecting Ruby applications to SQL Server through ODBC can unblock legacy setups when native adapters fail. sequel can use an existing ODBC DSN for database access.

RubyODBC fails to create an ODBC environment handle when connecting Ruby 1.8.7 on Ubuntu 10.10 to SQL Server 2005; rebuilding the gem with the correct unixODBC path restores connectivity.